Tanzanite, the debutant of the gem world and a December birthstone

Tanzanite is a recent debutant to the world of gemstones has been heralded by many as the Stone of the 20th Century. Its impact on the industry is undeniable, being elevated to Birthstone for December in 2002.  The legendary New York jewelers Tiffany and Co were the first to market the stone as a precious gemstone, in the rarefied echelons of Diamond, Emerald, Ruby and Sapphire.

A touchstone design:  Velvet Blue Daiquri Ring: Tanzanite and White Gold

There are only two known deposits of tanzanite in the world. A small and uneconomic deposit has been found in Kenya. While the main and only economic deposit islocated in the Merelani Hills near Ausha, Tanzania.  Estimates vary, but in all likelihood with consumption continuing at it current levels, the Merelani Hills deposits of Tanzania will be completely depleted within 20 years.

While Tanzanite is a relatively recent discovery, similar minerals were discovered almost two hundred years ago in the Austrian Alps.  Natural tanzanite is in fact a rather dull yellow-brown colour, and most tanzanite has been heat treated to produce the striking violet-blue colour.  When heated to 400-500 degrees C, the natural yellow and brown tints vanish and an amazing blue develops. The colour of the highest quality tanzanite is described at cobalt ultramarine. The most sought after colour  is a strongly saturated blue  displays a purplish almost amethyst undertone.

Tanzanite while a beautiful stone, has a low hardness (6.5-7) compared to other gemstones, and should be worn with care in all but designs that prevent the gem from being knocked or scratched.  Pieces such as earrings and pendants are great options over everyday rings . With care a master craftsman can create a ring for daily wear that does justice to the gem and protects is within certain limitations of design.

Tanzanite exhibits three different colours when viewed along each of the three major axis (x, y & z). This pleochroism from very strong violet blue to brown, means the stone appears different colours, when viewed from different angles. In daylight the appearance of the stone is more blue, while under artificial light a more Amethyst violet colour is seen in the same stone.  As a transparent Type 1 gemstone, most are eye clean except in very large pieces.

Large tanzanites are not uncommon, with the largest recorded cut stone to date being 731.81 carats. One of the most famous is the 242carat “Queen of Kilimanjaro” currently on display in the Gallery of Gold and Gems at the Royal Ontario Museum in Toronto, Ontario, Canada.

During the month of December, purchase any tanzanite on our website www.touchstonegems.co.za and get 20% off the purchase price. This offer is valid until 24th December 2010.

Tanzanite 10x10 Trillion, 4.25 carats

R 24,500.00
N ow R 19,600.00

Tanzanite 6.50 Round, 1.23 carats

R 3,444.00
Now R 2,755.20

Tanzanite 7x7 Trillion, 1.15 carats

R 4,347.00
Now R 3,477.60

 

 

For more information on tanzanite, or any coloured gemstone, please visit our website www.touchstonegems.co.za or email us on enquiries@touchstonegems.co.za

A brief history of Man Made Gemstones

Imitations of gemstones

Attempts to imitate natural gemstones have been made since before the time of Christ.  The Egyptians were the first to mimic the valuable stones with glass and glazing.  In 1758 a Viennese, Joseph Strasser, developed a type of glass which could be cut and which looked similar to a diamond.  Although the production and sales of these imitations called Strass, were prohibited, they did eventually find their way into the European trade.

Czechoslovakia was an important center for the glass-jewellery industry in the 19th century.  For costume jewellery, cheap glass was used.  For gem imitations, lead or flint glass with a high refractive index was used.  These imitations had a similar colour to that of the original, but certain physical properties such as hardness and lustre could not be satisfactorily imitated.  Therefore, it became the dream of scientists such as Verneuil to fabricate imitation gemstones that really replicated genuine stones in every physical characteristic.  It was only towards the end of the 18th century, that French scientist, Verneuil successfully synthesized rubies at a commercial price.

Green terbium glass

The Verneuil process is known as the Flame Fusion Process.  It is today, still the most common process used for gemstone synthesis due to low production costs and high crystal growth rates. Large numbers of flame fusion gemstones like rubies, sapphires and spinels are readily available. The powdered ingredients are fused together under a high temperature oxy-hydrogen flame. As the powder melts it crystallizes in successive layers. The curved growth layers are important identification features and can be observed under a 10x loupe or microscopic. Sometimes clouds of gas bubbles are visible.

Synthetically produced crystals are NOT classed as imitations by the gem trade, but rather as a separate group, in addition to natural gems.  In the trade, they are referred to as “synthetic”.

Synthetic gemstones

The first man-made gemstones appeared in the early 19th century.  It was only in 1910, when Verneuli successfully produced rubies (red corundum), sapphire (blue corundum) and diamondite that these synthetics became economically viable.  By 1926 synthetic spinels with excellent colour of other gemstones such as aquamarine, tourmaline and blue zircon were produced and are still used today.

Synthetic Aquamarine

The first synthetic emerald was produced in the 1930’s in the USA.  Synthetic emeralds are produced using either flux fusion or hydrothermal methods (high temperature, high pressure water system).  The flux fusion technique is rarely used in fashion jewellery or industrial applications due to very high production costs. This technique also poses the greatest threat to the gemstone trade as flux grown rubies have inclusion patterns that very closely mimic the patterns seen in natural counterparts.  By dissolving ingredients into molten fluids and crystallizing them under controlled conditions, the desired gemstone mineral is produced.

There is no synthetic gemstone on the market today that has had a greater impact n the jewellery trade than Cubic Zirconia.  Cubic Zirconia (CZ) came onto the market around 1978.  The first CZ was made in Russia as an optical stimulant used in their lazer industry.  CZ is made using microwave technology which generate the intense heat required to melt and re-crystalise Zirconium Oxide that has stablilized with Calcium or Yttrium in a process called skull melting.

A word on Cubic Zirconia

Cubic Zirconia is a diamond simulant, not a synthetic diamond. The latter, are diamonds that have been produced in a laboratory rather than naturally occurring, by such companies as General Electric and Mitsubishi.

Cubic Zirconia

A simulant, simply put, is a natural or in the case of Cubic Zirconia a synthetic material that can imitate a natural gemstone.  A successful simulant needs to exhibit similar properties to the material it is intended to simulate. In the case of a diamond simulant it needs to be hard (diamond has a hardness of 10 on the Mohs scale), display excellent brilliance, lustre and fire, and have a colour (or lack of colour) similar to the diamond it is impersonating.

For more information on synthetic and natural gemstones, and gemstone sales in South Africa, please go to our website and online store.  www.touchstonegems.co.za

Planetary Gemology - A monthy investigation of the metaphysical quality of gemstones

Recently, while looking for something to read, I stumbled across The Handbook of Planetary Gemology which is written by Richard S Brown and dedicated to His Divine Grace Srila A.C. Bhaktivedanta Swami Prabhupada.  I have always held a certain amount of fascination for astrology, horoscopes and birthstones and their influences on our lives.  I have therefore decided to give you some insight into the mystical powers of gemstones and how they can influence the well-being of their owners.

Yellow Sapphire

Each month, I will write a short blog on the power of it's birthstone.  Just like an astrological horoscope charts the location of the planets at your time of birth to determine your birth sign, each planet rules over one or more gemstones and these auspicious gems can help remove obstructions in various areas of our life by appeasing the destructive forces that these planets have on us.

I will provide a short translation of the Vedic Text which is a description of how the gem seeds were formed from the body of the demon Vala which is basically the standard by which the ancients established the value of a gemstone, it's identity and talisman properties.

Citrine

The astrological properties for Citrine and Imperial (Golden ) Topaz is the same as Yellow Sapphire, so the following planetary and astrological characteristics are for Yellow Sapphire.

PLANET	Jupiter
SIGN	Sagittarius
HERB	Ficus Religiosa
NUMBER	3
SYMBOL	2+
COSMIC COLOUR	Light Blue
ELEMENT	Ether
SENSE	Sound
BODY ORGAN	Ears
COSMIC FORCE	Neutral
ANATOMICAL SYSTEM	Fat
CHAKRA	2nd, Ajna
DAY	Thursday
TIME	One hour before sunset
SPECIAL INFLUENCES	Promotes general wellbeing and spirituality. Helpful in pregnancy, childbirth and marriage. Prevents jaundice and liver disease

Characteristics of the ruling planet:  Jupiter

Jupiter is positive so individuals will display grace and tact during their Jupiter period.  They acquire inner grace which radiates as confidence in order to attain their goals.  As Jupiter rules Sagittarius(fire) and Pisces (water) respectively, the constant journey seeking a spiritual home makes individuals prosperous in material things.  Jupiter is incompatible with Mercury and Venus.

Citrine, Golden Topaz and Yellow Sapphire should not be used with emerald or diamonds.  Specifically designed talismans and accent stones are an exception to this principle.

Colours in relation to social divisions:

Pale/colourless:  intellectual or priestly division
Orange overtones: administrative or military division
Yellow overtones: trade or farming division
Green overtones: clerical or labouring division

Notable Gemstone Quotes

The leading line from the movie "Gentlemen Prefer Blondes"

Men grow cold,
As girls grow old,
And we all lose our charms in the end.
But square-cut or pear-shaped,
These rocks don't loose their shape.
Diamonds are a girl's best friend.
Diamonds Are A Girl's Best Friend!


Vicky Shek, Christie's Hong Kong Jewelry Division
New Tang Dynasty Television

"After the crisis from last year onwards, I found that more collectors are looking for top quality jewellery and diamonds for the investment to keep the value and also for sale. So for rare stones, even  pink, yellow, blue red, green - these rare stones are very popular in this market."

 Tim Dabson, a DeBeers executive director

“We know people over 55 treasure diamonds but that's not so clear for the Ipod generation."

Jeweller Myles Mindham

"When times are tough, hard assets like diamonds are in greater demand because they will hold their value when inflation hits – and it will hit.”

Anonymous

"Did anyone notice the Burma ruby in the movie Expendables? Wow!"


Roni Rubinov, jeweller

"It's about the trust that was destroyed by the crisis. People are realizing now they need to have something tangible, not just a piece of paper."

Newsobserver Staff

"Indians thought of butterflies as gemstones of the gods, tossed from the heavens to spread beauty."

German jeweller Christian Hemmerle

"Red spinel gemstones are reminiscent of Queen Elizabeth's Timur Ruby."

Russel Shor
Gems and Gemology

"The European Union enacted its own ban on Burmese gems, followed in 2008 by a tightening of the U.S. measure that effectively banned all Burmese ruby and jadeite imports regardless of where they were cut. As a result, more than 50 ruby mines closed down in Myanmar, while buying by foreign dealers reportedly fell by more than half in the latter part of 2008."

Adnan Khan
The Journey of a Gemstone

"The key to appreciating a gemstone is to hold it in your hands, turn it to see the light dance as it refracts through the complex internal chemistry, and – if you want to wax esoteric about it – feel its energy."


Dr Michael Krzemnicki, director of the Swiss Gemmological Institute (SSEF)

"Spinel could be the hot trend of 2010 and beyond, and retail jewellers should be looking to stock more pieces using the gemstone,. Spinels are rarely treated. Heating experiments on spinels show no or only limited enhancement, apart from clarifying some of its turbidity. For me it is a very great pleasure that this stone is a very natural product."

Everything you need to know about Citrine, the other birthstone for November

Citrine is a  popular and affordable member of the Quartz group (which includes Amethyst). The name is a derivation of the French word, for the lemon yellow colour that natural Citrines exhibit. Today though most commercial Citrines are actually heat treated Amethysts and are more of a golden than lemon yellow colour. Depending on the source deposit the heat treatment can produce  colours from yellow to gold to orange brown and red shades of transparent quartz. The final result being dependent on the level of heat applied. In ancient times, Citrine was carried as a talisman against the venom of snakes and scorpions. Today they are known in some cultures as the merchant's stone and are associated with success and prosperity.

Citrine 10x10 Square, 4.83 carats

The causal element  that imbibes natural quartz with its lemon yellow colour is a trace amount of Iron (approximately 40ppm). Natural (untreated) citrines are mostly a  pale lemon yellow to golden yellow colour, but recent demand has meant that almost all of the commercially available stones are now heat treated Amethyst, which exhibit a reddish tint to the overall yellow to golden hue of the stones.
Purchasing Citrine

Colour
While natural Citrine is much preferred over the Citrine produced by heat-treating amethyst, it is often hard to source such material as much of the rough currently available, is pre treated at source before it enters the cutting process. Paler more lemon yellow colours are preferable over the darker red tinted treated stones. Although personal preference is always the most important guide.

Citrine 10x5 Marquise, 0.90 carats

Clarity
Citrine, like Amethyst is an abundant member of the quartz group, and as such only  transparent examples  with excellent clarity, should be considered for facetted stones. A lower transparency can be considered for en cabochon cut stones

Cut
Citrines come in a wide range of calibrated shapes and sizes, constrained to a certain extent by the level of colour banding or zoning present in the stone. Portuguese cuts have become popular in recent years due to the additional brilliance added by the extra facets, which allow for more highly zoned stones to appear as consistent colours.
Mineable Deposits

The most important deposits of natural citrine currently in production occur in Brazil and Madagascar. Other locations include Argentina, Myanmar (Burma), Namibia, Russia, Scotland, Spain and the United States.

Citrine - Common Treatments
Natural Citrine is untreated and will typically exhibit some colour zoning, which can be partially dissipated with moderate heating. Most commercially available Citrine in the market have been produced by heat-treating Amethyst. Brazilian Amethyst will turns a light yellow colour at 878oF/470oC, and then a dark yellow to red brown at 1022-1040oF/550-560oC.
Important & Famous Citrine

While the piece in question has long been lost in the sands of time, around 1300 B.C the bejeweled breastplate of Aaron, contained a Citrine representing one of the 12 tribes (Naphtali) of Israel  - Exodus 28:15-30


Citrine is the birthstone for November, sharing this position with Topaz

November Birthstones: Topaz and Citrine

Topaz is the birthstone for the month of November, and those born under the star sign of Sagittarius

There is limited consensus on where the name Topaz originated. The most plausible is that it is named after an island in the Red Sea formerly names Topazos, although today know as Zebirget. The complication arose from a time when all yellow, brown and even green stones were collectively known as “Topaz”.

Topaz comes in many colours naturally, including clear, brown, yellow, orange, red, pink and blue. The most common colour is yellow with a red tint; the most valuable is pink to reddish. The colouring agents are iron and chromium.

The fine golden-yellow variety, known as Imperial Topaz, is relatively scarce. Topaz colours are rarely vivid, and as such the vast majority of today's commercially available cut stones have been enhanced, including those we sell on our website.

Pure Topaz is colourless and transparent; it is only with the inclusion of impurities (trace elements) in the crystal lattice that colour is imparted to the stone. The common colours are brown, yellow, golden, orange, red, pink and blue. The coloring agents are iron and chromium.

Blue topaz

While natural blue topaz is rare, pale blue, pale yellow and white stones are commonly treated to produce the popular blue colours sold as: Sky Blue, Swiss Blue and London Blue.

Blue Topaz 10.00mm Round, 4.97 carats

White Topaz:

This naturally occurring colourless variety of Topaz has enjoyed tremendous interest in the past five years. As a natural, semi precious alternative to Diamond or White Sapphire, this stone is a cost effective alternative in everyday jewellery where a white stone is required.

White Topaz 10x5mm Marquise, 1.15 carats

Mystic  Topaz:
Displaying a kaleidoscope of iridescent colors, Mystic Topaz (also known as Mystic Fire Topaz), was first launched to the public in 1997. The popularity of Mystic Topaz increased dramatically when it was exhibited at the Tucson Gem Show in 2003.

Mystic Topaz is produced using a metallic vapor deposition coating process. This coating is applied to typically only the top (crown) of a facetted white Topaz. The treatment while hard wearing is only 1 micron or so thick, and can become abraded or even removed following polishing of the stone (when jewellery is cleaned), or from everyday wear and tear that will impart micro scratches to the stone surface, effectively cutting through the coating. The stones iridescent appearance changes depending on the light source and the viewing angle, adding to the fire effect of the treatment.

In addition to the iridescent fire colours, brilliant shade or blue, green and orange among others are also currently  being produced and marketed.

Mystic Topaz 12.00mm Round Concave Cut, 6.97 carats

Imperial topaz

This the most sought after of all natural Topaz. Its rich golden color is generally not enhanced by any kind of treatment.

Pink topaz

Natural pink Topaz is very rare and costly. The vast majority of pink topazes are heat-treated yellow stones that turn pink. Pink Topaz is also being produced in large quantities using a similar vapour depositing process as Mystic Topaz, this to satisfy the current worldwide demand for pink coloured stones.

Pink Topaz 12x12 Heart, 7.45 carats

Topaz is a very hard gemstone (8 on the Moh's scale) with a high refractive index thus making it ideal as an everyday gemstone.

Colour
For totally natural stones  the golden-yellow variety, known as Imperial Topaz,  yellow with a red tint or the most valuable pink to reddish stones are popular albeit at a price premium due to their scarcity. Without doubt the most popular colour is Blue topaz, followed by Pink and then the Mystic colours (all being enhanced stones)

Lighting
Topaz is a pleochroic stone, exhibiting different colour when viewed along different axis. No discernable difference is seen between natural and artificial light sources for viewing the stone.

Clarity
Topaz is a Type 1 clarity gemstone and as such only eye clean examples should be considered for purchase.

Cut
Topazes are generally  cut in the simple step cuts, although any cut can be encompassed. The cutting style for weakly colored stones tends to be the round brilliant cut, which imparts more colour to the stone, or any of the cuts where additional facets have been added to enhance the lustre.
Mineable Deposits

While the 18th century deposits of Saxony are today all but depleted, other major deposits had been found to replace the significant consumption of this gemstone. The largest current deposits are in Brazil (Minas Gerais, Esperito Santo)  Other significant deposits are located in Sri Lanka, Myanmar and Russia, with lesser deposits in Afghanistan, Australia, China, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, United States and Zimbabwe. Natural light blue topaz is also found in England (Cornwall), Northern Ireland and Scotland.
Topaz – Common Treatments

The most common treatments for natural rough Topaz  (colorless or very lightly tinted), is either neutron irradiation or  linear acceleration. which are use to create the Blue Topaz commonly available in most jewellers nationwide. Neutron irradiation  followed by stabilisation with heat is use to produce the Swiss Blue Colours (Baby Swiss, Light Swiss, Swiss, Top Swiss) through the strong blue colours (Korean Blue & Maxi Blue) to the dark London Blue Topaz (blue with a green/grey overtone) . The depth of colour in neutron irradiation is a function of  the length of time the rough material is exposed to the isotope Cesium 137. As reactor time is expensive so the darker colours  are sold at a premium over their light  counterparts. The perennially popular Sky Blue Topaz is enhanced using LINAC (linear acceleration) a less expensive enhancement method result in an Aquamarine coloured stone .

In  1997, a new type of enhanced Topaz made its appearance, the surface-enhanced Topaz, with colors described as blue to greenish-blue or emerald green.

The vast majority of pink Topazes are either heat-treated yellow stones that turn pink, or are the result of  a metallic vapor deposition coating process.

Displaying a kaleidoscope of iridescent colors, Mystic Topaz (also known as Mystic Fire Topaz), was first launched to the public in 1997. The popularity of Mystic Topaz increased dramatically when it was exhibited at the Tucson Gem Show in 2003. Mystic Topaz is produced using a metallic vapor deposition coating process. This coating is applied to typically only the top (crown) of a facetted white Topaz. The treatment while hard wearing is only 1 micron or so thick and can become abraded or even removed following polishing of the stone (when jewellery is cleaned), or from everyday wear and tear that will impart micro scratches to the stone surface effectively cutting through the coating. The stones iridescent appearance changes depending on the light source and the viewing angle, adding to the fire effect of the treatment.
Important & Famous Topaz

Topaz is a gemstone who's formation allows for the growth of some very large crystals. In 1967 a Blue Topaz of nearly 100kg (500 000 carats) was discovered in the Ukraine. The Smithsonian Institute in Washington has several large examples on display, including a single facetted stone weighing 22,892.50 carats, making it the largest cut yellow topaz in the world.

Perhaps the most famous Topaz is a giant specimen set in the Portuguese Crown, the "Braganza", which was first thought to be a diamond.
Topaz – The Legend

There are many  ancient stories and beliefs that have created an interesting history for Topaz. The Egyptians called Topaz the “Gem of the Sun,”  and believed it was colored by the golden glow of their sun god Ra and thus a powerful protector from harm.

Greeks and Romans also associated  Golden Topaz with their sun god, Jupiter. They believed the gem increased their strength and could neutralize spells and curses.

Topaz is mentioned in the Bible as being one of the “stones of fire” (Ezekiel 28:13–16) that were given to Moses and set in the breastplate of Aaron (Exodus 28:15–30). Topaz is also one of the twelve gemstones set in the foundations of the city walls of Jerusalem (Revelations 21:19) and associated with the Apostle Matthew.

Bushmen here in Africa used topaz in healing ceremonies and rituals to connect with ancestral spirits.
Topaz is the birthstone for November, and for those born under the star sign of Sagittarius.

Taken from www.touchstonegems.co.za

New Nigerian Red Tourmaline Find

Taken from: Gemstone Forecaster
Author: By Robert Genis

 
The Brazilian red tourmaline, Ouro Fino, was originally found in 1981. It was a killer red colour that looked like a ruby, but the goods were included to a degree similar to Colombian emeralds. Even with the inclusions, collectors coveted the gemstone. The mine was played years ago and the best stones are now sitting in collections. Many new gem dealers have never seen this stone. Red tourmaline was recently discovered in Nigeria in 1998. It came in purple, cranberry, orange/pink and multi colours. This material is long gone and most are sitting in collections or mounted in jewelry. Regretfully, none of this material was ever really red. Since the 1998 find, most of the Nigerian tourmaline material has been very low quality. The yield was low and most of the stones were cabochon quality. Last year, some very large pieces of the new red tourmaline were found in the Oyo Valley of Western Nigeria. Crystals weighing 15 and 48 pounds were found. This is unbelievable! Usually a few pieces are found here and there. The material was so large, the owners needed a tile saw to cut them. The new material is yielding about 15-20% from the rough. The great thing about it is some of the best material is bright red and at the same time clean. Until now, most red and pink tourmaline crystals were horribly included.

History
Tourmaline's name comes from the Sinhalese word "turmali," which probably means "mixed precious stones." Bright, rainbow collections of gemstone varieties were called "turmali" parcels. Sri Lankan (Ceylon) tourmaline was introduced to the European society in the late 1600s or early 1700s by Dutch traders. Similar to rubies which were later discovered to be spinels, numerous red gemstones in the Russian Crown jewels from the 17th century, once thought to be rubies, are actually tourmalines. The Empress Tzu Hsi, the last Empress of China, loved tourmaline and bought large quantities from the Himalaya Mine located near San Diego, California in the early 1900s.

Geology
Tourmaline is 7-71/2 in hardness and does not tend to chip or break. Its luster is glassy and it has a high degree of transparency. Tourmaline is a group that applies to several minerals with similar chemical compositions and atomic structures. Tourmalines belong to the hexagonal crystal systems. Tourmaline crystals begin as colourless and the red is created by trace elements.

Red/Pink colours
Corundum collectors and dealers argue over where to delineate a red ruby vs. a pink sapphire. With tourmaline, the argument is "what is rubellite vs. what is pink tourmaline?" Although the argument will continue, the new find has colours that can be broken down into four groups. The reddest colours have very dark 85-90 tones. Isn’t this always the case with many gemstones? It is almost nature’s trick. These stones are red but black out. Ideally, if you want pure red, choose the reddest stones that black out the least. Approximately 10% of the production is this colour. Generally, the best stones are red/pink with light tones. This open colour is highly desirable. Some say it is reminiscent of Burma ruby. This colour represents the majority of the material. The third colour is fuschia. This is the point in Burma rubies where the stones transition to pink sapphires. These stones have a balance of red and pink and look like pink sapphires. Finally, the last colour is a hot bubblegum pink like hot pink spinel. The last two colours represent 40%, or the balance of the material.

Sizes/Prices
The new material is available from 3mm rounds to stones of 15-20 carats. The largest stone cut so far is about 55 carats. Gemstone collection suites can presently be purchased in this new material. Relatively speaking, the new material is inexpensive. Top one carat sized stones start at $100 per carat. Prices for gem quality red tourmaline can escalate to over $500 per carat for serious large stones.

Treatments
We know today the original crystals were not irradiated or treated. The crystals are so large, they would never fit into a nuclear reactor, a particle accelerator a gamma ray facility. Ditto for heating the material. It doesn’t mean the material might not be heated in the future. However, the new Nigerian material is flying so fast out the door of the owner, they do not have time to monkey with the product.

Conclusion
Some predict the new material may be the next Ouro Fino rubellite. When those stones first hit the market, people immediately recognized the gems would be rare. The same can be said for the new red tourmaline. What makes this find interesting from a collecting standpoint is the goods are an inexpensive red stone compared to ruby and spinel. It might make sense to buy a suite of the various colours or specialize in one colour. If you always wanted to start a gemstone collection and were short on funds, this might be an excellent opportunity. Given the tight economic times, this just may be the right stone at the right time for the right price. Collectors who purchase these goods at the beginning of the market cycle might soon be sitting pretty.

Tourmaline - The modern birthstone for the month of October

There are fourteen different stones listed as birthstones for the calendar month of October, or as Sun/Star, Planetary, or Talismanic stones for the Zodiac sign of Libra or Scorpio. Birthstones for the calendar month of October are opal, tourmaline, jasper, aquamarine, coral, and beryl.

The Zodiac signs of Libra and Scorpio include eight additional stones: peridot, sapphire, lapis, agate, topaz, garnet, ruby, and amethyst.

Tourmaline is the veritable chameleon of the gemstone world. This popular stone is available  in more natural colours and tones than any other gemstone.  In addition to the stones being strongly  dichroic, (a single coloured stone will appear to have two different colours when viewed in different directions), many Tourmalines are actually zoned during grown across the crystal, and  exhibit  two or three colours in a single stone viewed on any axis.

Known for centuries in the Mediterranean countries, Tourmaline really  gained popularity when the Dutch East India Company began to import it into Europe in  the early 17th century from Ceylon. The name Tourmaline was chosen from the Singhalese word Turamali, to assist in the sale of this gem.

Tourmaline is actually the name of a group of related mineral species, although individual species names have been dropped in preference for the "global" terminology "Tourmaline".


What Causes The Colour?

As Tourmalines are part of a related family of mineral species, their basal chemical composition and trace element chemistry determine their colours. In simple terms they are best described as Aluminium Borate Silicates, of changeable composition.  Certain colours had been assigned specific names while others are merely prefixed with a colour before  the word Tourmaline.

Achroite: A colourless to near colourless variety
Dravite: A yellow brown to dark brown variety
Rubellite: Pink to red with or without a violet tint, with deep reds resembling Ruby.
Verdelite: A green variety, found in virtually all shades of green.
Chrome tourmaline: Another green variety, however this differs from Verdelite in that the colour is derived from the inclusion of trace amounts of chromium, resulting in rich Emerald green colours.
Indicolite: A blue variety, again found in almost all shades of blue.
Bi-Colour: Variations, zones and colour bands in Tourmaline are often purposefully accented with the cutting style to show bands and color zones in the gem. Occurring in uncountable colours variations, these are often seen in long acicular crystals.
Watermelon:– Bi-color Tourmalines which show a green skin and a red core
Canary: Bright yellow Tourmaline.
Paraíba: A rare blue-green Tourmaline. The causal element is copper imbibing the stone with an almost neon blue colour
Cat's Eye: Chatoyant Tourmaline in a variety of colors.
Colour - Change: Changes from green in daylight to red in incandescent light.

Other varieties may be simply sold with a color prefix, as in Pink Tourmaline, Green Tourmaline etc.

Purchasing Tourmaline

As with most coloured gemstones  an intense, saturated colour is the most desirable. Again personal preference dictating the colour a buyer will finally choose. In some cases the saturation of the colour can reach such a level that the stones appear almost black, as in some examples of larger Green Tourmaline. These should be avoided.

Tourmaline exhibits strong pleochroism, actually being dichroic, with two distinct colours. In either natural or artificial light these different colours or different shades of one colour  are similarly visible.

Different varieties of tourmaline tend to have differing clarities. Thus while large clean tourmalines in the blue and blue-green colors are common, almost all red and pink tourmalines will show inclusions of some kind. The most common inclusions are needles, fractures and  healed fractures.

While Tourmaline are cut in virtually any cut imaginable, the stones strong pleochroism must be considered. Tourmaline is commonly cut parallel to the longest axis of the rough crystal, in rectangles and rectangular emerald cuts (in both step and princess patterns). In this orientation darker Tourmalines exhibit the lighter of the pleochroic colors, which makes for a more pleasing stone.

Lighter Tourmalines are typically cut across the longest axis of the rough crystal, such that the table in the finished stone is parallel to the shortest axis of the crystal. This ensure that the darker of the pleochroic colours is seen when  the stone is viewed from the top.

Cabochon cut although common tend to be reserved for examples of lower clarity material.

Mineable Deposits
While Tourmaline deposits are found the world over, the most productive mines are found in Sri Lanka, Madagascar and Brazil. Lesser deposits occur in Mozambique, Zaire, Australia, Myanmar, India, Zimbabwe, Namibia, Tanzania, Thailand, Russia and the United States.

Tourmaline beach cliffs in the United States

Common Treatments
The heat treatment of Tourmaline is commonplace. Heating between 450-650 degrees Celsius produces subtle colour changes, which enhance the appearance and value of the stone. Indifferently coloured greens can become rich emerald greens, pale Paraiba and other Blue Tourmalines also benefit from heat treatment to deepen and intensify the colour.

Important & Famous Tourmalines
The Empress Dowager Tz’u His, the last Empress of China, was so taken by Tourmaline that it is rumoured she purchased nearly a ton of it for her personal collation.

The Legend
More of an interesting fact than a legend is Tourmalines ability to become electrically charged. A small electrical current can be induced in the stone, by heating, cooling or applying pressure. All three of these can be achieved by simply rubbing the stones, and accounts for the stone being known as Aschentrekker (Ash Puller) in the days of Meerschaum tobacco pipes.

Taken from Touchstone Gems www.touchstonegems.co.za 
and http://www.bernardine.com

October Birthstone: Opal

Opals come in a variety of colours

Opals are most prized for their unique fiery play of colour, reflecting and refracting light into brilliant flashes of multiple colours. The true source of this play of colour was mistakenly attributed to Adularescence until the invention of the scanning electron microscope. Subsequent  analysis at 20 000 time magnification uncovered the true cause of the effect we know today as Opalescence.

Opal is hydrated silicon dioxide, containing from three to twenty percent water. This feature coupled with its low hardness of 5.5 - 6.5 on the Moh's scale, means that Opals require special care as a gemstone

Colours: Various
Hardness: 5.5 - 6.5
Refractive Index: 1.37 - 1.52
Specific Gravity: 1.98 - 2.50
Crystal System: Amorphous
Enhancements: May be enhanced
Major Sources: Mexico, Australia, Tanzania, Zimbabwe, Brazil

Warnings for Care
Soft, brittle  very susceptible to physical damage / heat

Opal Facts
Opal has a distinguished history dating back to pre Greek, Indian Sanskrit times. The name is derived from  the Indian Sanskrit word for stones  "upala". Three groups of Opal exist, precious opal, fire opals and common opals.

Opal - What Causes the Colour
The body colour or matrix in Opal  can be white, colourless, pale yellow, pale red, brown, gray or black depending on the host rock and the level of impurities.  Internal diffraction of light causes  flashes of any color across the entire spectrum (opalescence). The physical structure of opal is unique, with tiny spheres of silicon dioxide having orientated themselves during the solidification of a mineraloid gel, into pyramid shaped grids interspersed with water molecules.  A combination of the size and spacing of the spheres and tiny natural faults between the grid layout, causes light to be split into its constituent spectrum of colours, which results in the characteristic play of color. While the diffraction and interference can express itself as every colour in the visible spectrum, each Opal is unique in terms of its internal structure and the colours observed. Precious above all other varieties displays multispectral hues that change with the angle of observation.

Precious Opals
Black Opal, is the "King of Opals" which is a precious opal with black matrix color. The high contrast between the matrix and the opalescence ensure this variety has the highest play of colour.  White Opal, is also considered a precious Opal with white or very light matrix colour.

Fire Opals
Fire Opals are names after their orange colour, they do not opalesce and are generally milky or turbid in appearance.

Common Opals
Common Opals are mostly opaque, and devoid of the characteristic play of colour seen in Precious Opals.

Purchasing Opal
When choosing an opal, the lay of colour, matrix color and degree of transparency are the most important criteria which determine the price of precious opals.

While popular Opals are delicate gemstones, prone to dehydration, cracking, scratching and fading. When not being worn it is suggested that they be kept in a humidified environment (60-70%) such as in a plastic bag with a pierce of damp cotton wool, or in a cigar humidor.  For jewellery pieces Opals are better suited for earrings, brooches, and pendants, than rings and bracelets.

Colour
The higher the play of colour and the darker the matrix (for contrast) the more expensive the stones. The exception is Harlequin Opals, where the play of light can be relatively simple but the pattern in important with strong geometrical pattern being sold at a premium

Lighting
Opal looks best viewed in natural especially in the softer early morning or late evening light where the play of colour is maximised.

Clarity
Precious Opal are acceptable in, opaque, transparent or  translucent grades of clarity. The latter are rare and command a price premium

Cut
Mostly round or oval cabochon cut. Fine quality fire opals are facetted, although they are turbid rather than clear.

Mineral Deposits
Historically the main deposits were in Czechoslovakia, however since the early 1900's Australia has been the pre eminent producer of most of the world precious Opal. Currently about  85 percent of the world's supply of white precious opals is mined from the famous deposits at Lightning Ridge, White Cliffs, Coober Peddy and Andamooka.  Other deposits are found in Mexico, Brazil, Guatemala, Honduras, Indonesia, Russia and the United States.

Opal - Common Treatments
Opal are typically impregnated with oils, waxes, or plastics as part  a fracture filling enhancement. This markedly improves the appearance of the stone although over time the effect can be lost, and if the wax or oil decolours then some of the play of colour may be lost.

Important & Famous Opals
There are numerous examples of large Opal in existence, three of the largest ever discovered are, the " Andamooka Desert Flame" (6843kg), Big Ben" (4000 carats), and the "Light of the World" (2250 carats,

Opal - The Legend
According to the Aborigine legends, the creator came down to Earth riding on a rainbow, in order to bring the message of peace to all the mankind. Where his foot touched the ground, the stones became alive and started sparkling in all the colours of the rainbow. That was the birth of the opals.

Taken from:  www.touchstonegems.co.za

The allure of coloured gemstones in engagement rings

Fascination with coloured gemstones dates back to the very beginning of civilization. Long before the discovery of diamonds, the blue sapphire evoked visions of heaven; the red ruby was a reminder of the very essence of life. As early as Roman times, rings containing coloured gemstones were prized as symbols of power and friendship. In fact, the most powerful; and the most beloved, wore rings on every joint of every finger, reflecting the status of their position!

As Betrothal rings, coloured gemstones also hold an illustrious position. In addition to the beauty of particular colours, certain powers attributed to certain coloured gems made them not only beautiful but also meaningful choices. We see many examples of coloured gemstones in engagement and wedding rings, from many centuries ago to the present, used both alone and in combination with diamonds.

Following the discovery of diamonds in South Africa, which made diamonds more widely available and affordable, coloured gemstones were briefly ignored during the earlier part of this century. While there always has been people who preferred coloured gemstones despite the trends, coloured gemstone engagement rings have only recently re-emerged as a choice for the modern bride. The selection of a sapphire and diamond engagement ring by His Royal highness Prince Charles for lady Diana, followed not long thereafter by his brother Prince Andrew's selection of a ruby and diamond engagement ring for Sarah Ferguson, sparked a revival of interest in coloured gemstones for the bride to be.

While rubies, sapphires and emeralds have historically been among the most coveted gems, particularly for important occasions, there are many alternatives in coloured gems for today's bride, depending on budget and the personal connection to bride herself. Keep in mind that most birthstones come in several colours. You may be surprised to learn that the colour you associate with your birthstone may be only one of several colours in which the gemstone occurs.

For example, most people think garnet is dark red and are surprised to learn it can be emerald green, mandarin orange, yellow, white, purple; virtually every colour in the rainbow except blue. If you have discarded your birthstone as a choice because you don't care for its colour, check out all the colours in which it may be available before making a decision. Some colours in a particular gem may be rarer and less readily available and often costlier than better known colours, but the friendly staff at Touchstone Gems can work with you to discover your alternatives. One can combine a birthstone with diamonds, blending the symbolism of diamonds with the personal significance of the birthstone for a lovely, deeply meaningful, and often much more affordable ring.

In addition to birth gemstones, the choice of a particular coloured gemstone may be connected to mystical powers, attributes, or symbolism with which the gemstone has been historically identified. There is an almost limitless wealth of information about coloured gems, enough to stir the imagination of even the greatest cynic.

Love rings and "Sentimental" jewellery

Throughout history, coloured gemstones set in rings and other jewellery have carried hidden messages. We are seeing similar pieces being produced today. For example, a ring containing diamond, emerald, amethyst, ruby, emerald, sapphire, and topaz, arranged in that order, spells the word "dearest" if one takes the first letter of each word, thus carrying the sentiment that wearer is more dear than any other to the giver; a ring containing pearl, ruby, emerald, and sapphire spells "pres," which, in French, means "near" and suggests that the wearer is always near to the giver; amethyst, moonstone, opal, ruby, and emerald spells "amore," which is Italian for "love." And so on. Such a ring can create a wonderful, "sentimental" engagement ring.

Choosing the shape of a gemstone

Today's bride-to-be has more choices in engagement ring design and style than ever before. But the first step in creating the look you want is selecting the shape of the gemstone, a shape that is right for you. There are many shapes from which to choose, but it's important to choose the right shape because it will affect the overall design and look of your ring.

1. Round brilliant

2. Pear shape

3. Marquise shape

4. Oval shape

5. Octagon shape

6. Heart shape

7. Square shape

8. Baguette shape

9. Trillion Shape

Today, in addition to the classic shapes, there are many popular "fancy" shapes from which to choose.  Some of the new shapes lend themselves to very distinctive designs that would be difficult to create with other shapes; some exhibit unique personalities, not possible in any other; and some can even help you stay within your budget (some appear larger, for their weight, than traditional cuts, enabling you to get the size you want in a gemstone that actually weighs less than you might have thought you need). One of the most exciting parts of searching for your ring is discovering what is available today!

You should keep in mind, however, that fancy shapes, new and old, can be vary in their width and length, and in their basic proportioning, and these differences can result in a totally different look and feel on your hand. For example, an emerald cut gemstone that has a octagon shape will look very different from one that which is square; a broad shouldered pear shape might look too triangular for the hand, while one with softer, more rounded shoulders might be just what you want. To some extent, the choice of shape is a very personal matter, and there is no standard "ideal" range that is applied to shapes other than round, but you must be careful that the stone is not cut in such a way that is liveliness and brilliance is reduced or adversely affected.

As you begin to look at gemstones, try on all of the shapes; you may discover you like a shape you might not have considered otherwise! Try them in solitaire style and in designs that incorporate smaller gemstone accents. It won't be long before you have a clear idea of the shape that best suits your personal style and taste, the shape that you really like best.

Again, the use of side gemstones to accent a center stone (diamond or coloured gemstone), and the shape of the side stone, is a matter of personal choice. In addition to the shapes mentioned here, almost any of the other popular shapes can be found in small sizes and can be used to create an interesting and distinctive ring.

We would like to thank Bijan Aziz , the owner and Web Master for The Jewellery Hut for allowing us to use his copy on our website, in our blogs and newsletters.

Sapphire imagery

We have many beautiful loose sapphires in stock.  Whether you are looking for a round, oval, marquise, square or pear shape, we have them all (plus many more) in a variety of sizes and colours.

As mentioned in my Sapphire blog, Sapphire and Ruby are members of the Corundum family. Pinkish red, red and reddy brown stones are called Rubies. All other colours of Corundum are termed Sapphires.  To most people a Sapphires is blue, but they actually come in all colours from black to white. Corundum is second only to Diamond in terms of its physical hardness, (although exhibiting only 1/140th of the hardness of Diamond), This hardness (9 on the Moh's scale) in relation to all other gemstones has ensured Sapphires position with Ruby and Emerald  as one of the so called "precious gems".

2.26 carat 7mm round sapphire

1.89 carat 8x6mm oval sapphire

2.10 carat 8x6mm oval sapphire

Matched pair 1.89 and 2.10 carat ovals

2.63 carat 8x7mm oval sapphire

2.45 carat 9x7mm oval sapphire

1.33 carat 6.5mm round orange sapphire

1.68 carat 8x6mm oval pink sapphire

0.92 carat 7x5mm oval red sapphire

0.93 carat 6x5mm oval red sapphire

1.28 carat 7x5mm oval red sapphire

1.38 carat 7x5mm oval yellow sapphire

2.14 carat 7x6mm oval yellow sapphire

2.42 8x6mm oval yellow sapphire

2.65 carat 8x6mm oval yellow sapphire

If you are interested in any of the above sapphires, or if you would like to have our price list, send an email to Sales enquiries or call us on +27 11 788 3629

September Birthstone: Sapphire

Colours	Various
Family	Corundum. Al203
Hardness	9
Refractive Index	1.76 – 1.78
Specific Gravity	3.97 – 4.05
Crystal System	Cubic
Enhancements	May be Enhanced
Major Sources	Namibia, Nigeria, Sri Lanka, Mali, India Kenya, Zambia, Mozambique, Tanzania, Russia, Madagascar
Warnings for Care	Colour change occurs at moderate to high heat

Sapphire Facts

The name Sapphire come from the Greek word for blue, although in the middle ages the name was applied more to what we know today as Lapis Lazuli. Sapphire and Ruby are members of the  Corundum family. If Corundum exhibits a colour from slightly pinkish red, through red to slightly reddy brown then it is called a Ruby. All other colours of Corundum are termed Sapphires. So while we traditionally think of Sapphires as being only blue stones, they actually come in all colours from black to white.  Corundum is second only to Diamond in terms of its physical hardness, (although exhibiting only  1/140th of the hardness of Diamond), This hardness (9 on the Moh's scale) in relation to all other gemstones has ensured Sapphires position with Ruby and Emerald  as one of the so called "precious gems".

Sapphire is the birthstone for those whose birthday falls in September, and for those born under the star sign of the Taurus.

Sapphire - What Causes The Colour

In Blue Sapphire the causal agent is trace amounts of Iron or Titanium, a  violet hue being caused by the presence of Vanadium. When the trace content of Iron is very low, yellow and green tones are produced. While the inclusion of Chromium in the lattice produces a pink colour in the stones. Blue is however the most famous and desired of the sapphire colors. The prized Kashmir and Burmese Sapphires have a deep intense almost velvety blue colour, and represent the pinnacle of colour perfection.

Padparadscha from the Singhalese word for  lotus flower, is a very rare sapphire which exhibits two colors simultaneously, pink and orange, and like Ruby and unlike all the other fancy coloured Sapphires has its own name. This being due to its rarity and value.  Purple is another rarer colour for Sapphire, being  found in Sri Lanka and Tanzania. In these deposits Iron and Titanium which normally produce the common blue colour, has under specific concentrations and conditions caused the purple hue of the stone.

Colorless or white Sapphires are rare as faint shades of color (typically blue and pink) are nearly always present.  Many of the fancy coloured Sapphires are under microscopic examination merely combinations of banding in two distinct colours. Green for example is actually the result of closely space blue and yellow colour band within the stone.

Purchasing Sapphire



Colour
All Corundum’s (Ruby and Sapphire)  are graded on  the purity of their primary hue or colour. For blue Sapphires, the primary hue is blue, while violet, purple and green are the normal secondary hues. Violet and purple can contribute to the overall beauty of the color, while a green overtone is considered a negative trait and it to be avoided. Blue sapphires with typically a primary Blue hue comprising 85% of the colour and secondary (violet or purple) hues contributing 15% to the colour are said to be of fine quality. Blue sapphires with any amount of green, a distinct negative, as a secondary hue are less attractive and  not considered to be fine quality. A Gray tone is a normal and common saturation modifier or colour mask in blue sapphires, this effectively reduces the saturation or brightness of the hue and therefore has a distinctly negative effect on the stones appearance and value


Lighting
Sapphires are a daylight stone looking their best when expose to natural sunlight. After dark or indoors, they still look very attractive under fluorescent light. Incandescent (tungsten) light  which is a soft light found in all but the latest energy saving globes is a redder, warmer light, which does no real justice to the gem, making them appear dark and dull compared to their appearance in daylight.


Clarity
Second to colour, clarity is the next most important criterion to consider when purchasing a sapphire. Good quality stones should be clear of visible inclusions to the naked eye or eye clean. Sapphire tends to be cleaner than ruby and larger unincluded pieces are not uncommon. Under microscopic examination almost all sapphire are actually included. The presence of a find rain of inclusions or fine needles within the stone can impact significantly on the appearance of the stone in a distinctively positive way. The famed Kashmir Sapphires has a rich almost velvety appearance due in part to the presence of fine inclusions, not visible to the naked eye. Star Sapphire (Asterism)  is common in those stones with a high content of fibrous or needle like inclusions, typically needles of Rutile. The star manifests itself as a 6 rayed or pointed star when view from above in a en cabochon cut.


Cut
No one cut particular  favours the natural beauty of Sapphires. As such all cutting styles are commonly produced, with rounds dominating the smaller sizes and ovals and oval or square cushions in the larger sizes. Lower grade slightly less transparent rough is often cut  en cabochon or as round brilliants where the added brilliance the cut imparts to the stones  can help to mask their lower quality. Those stones with a high Rutile needle content are cut en cabochon with care being taken to ensure the orientation of the needles in the finish piece creates a centered, symmetrical and clear star effect.

Mineable Deposits

Sapphires are abundant in many localities around the world, although some of the once prolific producing areas are now heavily depleted, or completely worked out. Historically the mines of the Kashmir region of India and Mogok valley in Myanmar (Burma) have produced some of the finest material known, but today production is limited and care should be taken when purchasing stones at a premium based on their provenance. Significant deposit are located across South East Asia, (Thailand, Vietnam, Cambodia and South East China). In addition Sapphires occur in Africa (Tanzania, Kenya, Nigeria and Madagascar), Australia and Sri Lanka.

In the 1980's about 70% of the world Sapphire production was coming from the Australia, although the quality was of a commercial nature, rather than top gem quality. In recent decades this dominance has declined. Today Sri Lanka and Madagascar produce most of the fine sapphires finding their ways on to the worlds rough markets

Sapphire - Common Treatments

Heat Treatment
Sapphire like their cousins Rubies are commonly heat treated to enhance their colour and to even out or totally remove "silk". While initially only stones of a lower quality were treated in this way, estimates coming for South East Asia indicate that heating is now carried out of about 95% of all rough material, as part  of an industry accepted enhancement technique. Heat treatment is used specifically to improve and even out the colour in Sapphires, and when done at a moderate heat will reduce the presence of needles. At higher temperatures needles, specifically of Rutile are completely removed by a process of melting and re absorption. These heat treatments enhancements  typically occur around temperatures of 500  - 1800 °C, in computer controlled electric furnaces. Some cutting houses still use the older process of low tube heat, when the stones are heated over charcoal at a temperature of about 1300 °C  for 20 to 30 minutes, a process know in the trade as "Chanthaburi cooking". The silk is only partially broken as the color is improved, imbibing the stone with a richer luster, and better colour.

Diffusion Treatment
The diffusion technique is essentially a method of coating a natural Sapphire with a "skin" of colour. The compound for diffusion is effectively bonded into the outer layer of the cut stones as they approach their melting point, thus forming a composite lay of essentially Sapphire and the diffusion agent on the stones surface. The depth of this colour enhanced skin can vary  from a few microns to an millimeter or more depending on the method used. Initially this was confined to blue Sapphires of a lower blue or  green colour, and the diffusion coating was Titanium oxide, which imparted a deep blue colour to the stones. Recently Beryllium is being diffused into the surface of  fancy yellow and pink sapphires at very high heat, and again close to their melting point.  This process  produces stunning red and orange colours that are only rare and expensive in nature (Padparadscha).

Important & Famous Sapphire

Very large sapphires are as a rule rare and as such are sometimes named in the same way as diamonds. One of the largest facetted blue Sapphires is the 423 cts Logan Sapphire currently on display at the Smithsonian Museum of Natural History in Washington. Other famous ones are the Midnight Star, the Star of Asia,  and the Star of India. In the case of the latter at 536cts this is the largest cut Star Sapphire known, and currently resides  in the American Museum of Natural History in New York.
The British Crown Jewels hold two exceptions blue Sapphires, the St Edward's and the Stuart replicas of which are on display at the Tower of London.

Sapphire - The Legend

Sapphire is the birthstone for those who are born in the month of  September, and for those born under the star sign of  Taurus.

Through history, Sapphire has symbolizes truth, sincerity, and faithfulness in relationships, bringing peace, joy and wisdom to the wearer and owner. In the past, Sapphires was also believed to be a talisman that would protect against evil spirits.