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.