Posts Tagged Spessarite
The Green Garnet
Posted by Michael Wall Bepsoke in The Gems of Information on January 27, 2013
Queue the Billy May orchestration, the Al Hirt trumpet solo and it’s the makings of a superhero movie.
For the purpose of this post it’s only going to be about a gem where in one of its rarest forms is an indicator in the search for Diamond. A gem that is used as an abrasive, as a sandpaper substitute in cabinetmaking and in some instance for cutting steel. A gem that was also used as ammunition.
Januarys birthstone Garnet is commonly seen in its red or reddish brown form but is in fact one of the lesser known gems. There are six recognisable species of Garnet, with at least 17 varieties. As with a lot of gems, Garnet will share a crystal structure but it is the chemical composition that gives them colour.
Unusually among gems Garnet will exist in hybrid from. That is, a mix of two or more of the species.
Let me start with the lesser known Garnet varieties.
Demantoid: An outstanding gem and highly desirable. It was used by Peter Carl Fabergé to encrust the Jewellery of the Russian Tsars as it had a similar dispersion to Diamond and exhibited a staggering array of rainbow coloured light. Not discovered until the mid to late 1800’s it is relatively new, yet occurs in different shades of green. From a pale yellowish green to a rich Emerald colour, the Demantoid commonly occurs in sizes no greater than 0.60ct. Stones above 1.00ct are rare.
Demantoid will include needle like inclusions that take the name ‘horsetails’. They do resemble wisps of tails or a mane, and are important when identifying the gem.
Tsavorite: A most wonderful variety of Garnet of the grossular species.
Tainted by murder, intrigue, and government controls, this gem only became recognisable by the use of a strong marketing campaign by Tiffany & Co.
Before that it was known as a green grossular and more familiar to gemmologists. Unlike Demantoid it takes its colour from chromium, and iron.
Spessarite: Possibly one of the most unique Garnet species. It occurs in one basic colour and one colour only. Orange. This is why it is sometimes given the name the ‘Mandarin Garnet’. It receives its colour from one fundamental element; manganese. First identified in Spessart, Bavaria the Spessarite is now commonly found in Namibia and Nigeria. Most have a sleepy or hazy appearance due to the fine inclusions and innumerable minute crystals.
As I mentioned earlier Garnet can occur in hybrid from. Mali Garnet is a hybrid of both grossular and andradite Garnet, and Rhodolite is a mixture of pyrope and almandite Garnet. Rhodolite occurs in a Purple colour.
Falling into the the grossular species is the Leuco Garnet, which as the name suggests is in fact colourless.
So from colourless through to orange, up to red and purple there is more to Garnet than meets the eye. Coupled with the rare greens, Garnet isn’t just a dull red stone. True, the reds are no Rubies, and the Tsavorite no Emerald, but these rare Garnets can command a €10,000 per carat price.
They are a precious gem in their own right.
Few little facts:
Garnet is the Birthstone for January.
It can be given on both the 2nd and 6th Wedding Anniversaries.
Garnet will not occur in Blue.
In early biblical writing, it was referred to as a ‘carbunculus’
Garnet gets its name for the Latin ‘granatus’, Greek ‘granatum’ meaning seed like.
Garnets were used by the Hunzas as ammunition. It was said the Garnet could add ferocity to the wound.
On the Mohs Scale Garnet ranges between 6.5 and 7.5
Should you contemplate buying a Garnet, do let me know. I’m happy to guide you through that purchase and give you some tips on what to look out for.
Do please leave a comment, a question if you have any, and your thoughts.
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Many thanks for looking