January Birthstone: Garnet

Some confusion reigns over the origin of the word Garnet. The most commonly held view is that Garnet is derived from the Latin word "granatus" meaning "grain", this from its typically rounded seed shaped crystals that resemble those of a  pomegranate "Punica Granatum". It may however come from the middle English word  "gernet" meaning deep red. Regardless Garnets have been widely known for thousands of years, as both a valued jewellery item and an abrasive. There are six common species of Garnet exhibiting a range of colours including red, orange, yellow, green, purple, brown, black, pink and colourless. For many years it was believed that Garnet did not occur in any form of the colour blue, however  following a discovery in the late 1990s in Bekily, Madagascar, the rarest of Garnets now shares its place among its peers. In some instance a single stone can exhibit more than one colour depending on the ambient light source (colour change Garnets). The most common colour  is red.

Garnet 12x12 Cushion Checkerboard, 9.78 carats

R 1,672.73

Garnets are hard (7 to 7.5 on the Mohs' scale), practical, everyday gemstones, being durable and resistant to  wear and tear, and relatively easy  to work with in jewellery manufacturing.  The latter owing to their resistance to heat. Garnet is the birthstone for month of January, and those born under the star signs of Capricorn and Aquarius


Garnet - What Causes the Colour
The colour of Garnets is as much a function of their specific chemical composition as it is the addition of trace elements within their crystal lattice. Garnets are a large family  of gemstones, with six distinct members or species, their chemical composition ranges from Magnesium Aluminium Silicates, through Iron Aluminium Silicates to Manganese Aluminium Silicates. Calcium Aluminium silicates, Calcium Iron Silicates and Calcium Chrome Silicates make up the other three species, all contributing to the wide range of colour found within the family as a whole

The Major Varieties:
Pyrope - red garnet, frequently with brown tint, Almandine - red garnet with violet tint, Spessartite - orange to red-brown garnet. The best specimen comes from Namibia and is called "Mandarin or Holandine Garnet". Rhodolite - purplish red or rose-colour garnet; Tsavorite - green to emerald green garnet and Demantoid - one of  the most valuable garnet, green to emerald green.

Tsavorite 6x6 Cushion, 1.21 carats

R 9,074.85

Purchasing Garnet:
As with any stone personal preference as much as fashion dictate which colour will be popular from time to time. Traditionally an intensely saturated deep red was the most common colour  and fine examples of this come from Mozambique. In larger sizes this deep red can become a little to overpowering and the stones appear somewhat dull as light struggles to be transmitted. As the public awareness for Garnets varieties develops so the demand for different colours has increased and subsequently their prices. Of late Demantoid with its rich emerald green colour has become one of  today's most valuable garnets, possible only second to the rare blue Garnet from Madagascar. Since the late 1960's Tsavorite, with it beautiful emerald green colour has been attracting attention and large examples now fetch a premium on world markets.

Lighting:
Garnet is a stone that looks as good under natural light as it does under artificial light. The exceptions are the colour change Garnets. Several  varieties of colour change garnets exist, and in natural light, their colour ranges from shades of green, beige, brown, gray, and blue, but in artificial light, they appear a reddish or purplish/pink colour.

Clarity:
As a family Garnets are in general very clean gems, certainly in smaller sizes. Larger examples of Pyrope can have small inclusions visible to the naked eye, however these rarely detract from the overall appearance of the stone due to their intense colour, and should not be seen as a hurdle in the purchase thereof.  Andradites as a family can contain a distinctive horsetail type of inclusion, and Almandines are know is some rare example to exhibit Asterism. The presence of asbestos and asbestos type fibres result in 4 and occasionally 6 rayed stars being visible in cabochon cut stones. Inclusions while usually a detractor from  the value of a stone, when rare as in the case of Garnet astertism,  can considerably enhance the open market price.

Cut:
Garnets lend themselves to all type of cutting, and no modern or historical cut really takes preference as being better to bring out the stones full potential. Suffice to say that as with all gemstones rounds are the most common followed by ovals, squares, octagons and pears.

Deposits:
China, Madagascar, Myanmar, South Africa, Sri Lanka, Tanzania, USA, Brazil, China, Kenya, Madagascar, Myanmar, Namibia, Sri Lanka, Tanzania, USA, South Africa, Sri Lanka, Tanzania, Russia.

Rhodolite 10x8 Oval, 3.34 carats

R 433.83

Garnet - Common Treatments
Garnet is not known to be artificially enhanced in any way. Synthetic garnet in the form of YAG (Yttrium Aluminium Garnet) was a popular diamond simulant in the 1970's, before it was eclipsed by Cubic Zirconia. However this clear variety of synthetic garnet is unlikely to be confused with the natural stone.

Important & Famous Garnets
Garnet has been a popular gemstone for jewellery for thousands of years. In recent times at the auction of the Estate of the late Jacqueline Kennedy-Onassis at Sotheby's on April 24, 1996, a Garnet cabochon flower brooch was sold for $145,000. In the same year a university student in Australia discovered what is believed to be the largest single garnet find ever. This giant rough is thought to weight thousands of tons and measures nearly a hundred feet across.

Garnet - The Legend
Garnets have been widely known for more than 3000 years,  from Egyptian, through Greek and Roman times, travelers wore Garnets for protection, as they were considered a popular talismans and protective stones, against evil.

During the month of January, we are offering a 20% discount on all Garnets, including Tsavorite.

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