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EXPERT ANALYSIS ACROSS A RANGE OF SECTORS

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Red garnets have a long history, but modern gem buyers can pick from a rich palette of garnet colours: greens, oranges, pinkish oranges, deeply saturated purplish reds, and even some blues. Red garnet is one of the most common and widespread of gems. But not all garnets are as abundant as the red ones. A green garnet, tsavorite, is rarer and needs rarer rock chemistries and conditions to form.

Where are Garnets found?

Garnet stones can be found in countries such asÃ¯Â¿Â½Brazil,Ã¯Â¿Â½Botswana, Tanzania, Kenya, Iran, Afghanistan, India, Thailand and Russia.

Quality factors of Garnets

Colour

Garnet includes affordable dark red varieties, rare and valuable greens, and many colours in between. Pyrope and almandine range in color from purple to orangy red. Spessartine is found in a variety of orange colours, while andradite comes in yellow and yellowish green. Grossular has perhaps the widest colour range of any garnet species, from colourless through yellow to reddish orange and orangy red, to a strong, vibrant green.

Gemmologists and coloured stone dealers further subdivide some garnet species into varieties depending on colour. For example, demantoid is a brilliant green variety of andradite that is highly prized by collectors. Both tsavorite and hessonite are varieties of grossular. Tsavorites are green, while hessonite ranges from orange and orangy red to brownish red. Rhodolite is a purplish red variety.

Clarity

Typical garnet clarity depends on garnet type. For example, the red garnets almandine, pyrope, and rhodolite typically do not have eye-visible inclusions. Some of the orange garnets, like spessartine and hessonite, often have eye-visible inclusions.

Garnet 5

Grossular is typically translucent, making it popular for cabochons, beads, and carvings.

Cut

Many garnets are cut into standard shapes and calibrated sizes to allow setting into manufactured jewellery. This is especially true of many red garnets. Expensive garnets like fine-quality tsavorite are cut into shapes and cutting styles that allow more of the weight to be retained from the rough.

Demantoid is often cut to exact proportions that allow the best possible display of its fire. Garnets are also popular for designer cuts and carvings. Red garnets are classic materials for cutting into cabochons and beads. They are commonly found to have high clarity and to be very transparent.

Carat Weight

Garnets can be found in all sizes and weights. Some garnets, like demantoid and tsavorite, are more commonly found in small sizes, so their value goes up significantly with size.

Other garnets, like almandine, are far more common in larger sizes so there is no dramatic rise in value as size increases.

Quick Facts

Chemical Composition: Various aluminium and / or calcium silicates
Refractive Index: 1.714 - 1.888
Birefringence: None
Specific Gravity: 3.47 - 4.15
Mohs Hardness: 6.5 - 7.5

* Information courtesy of GIA

Send AnchorCert Gem Lab your Garnets for testing!

AnchorCert Gem Lab, which is a division of Assay Office Birmingham, provides a Gem Identification service that is available for all gemstones. A stone will be assessed visually by qualified gemmologists and also tested for the basics such as its refractive index and specific gravity to help identify the material. Gemmologists have the knowledge and experience to detect the tell tale signs of imitations and treatments giving you complete reassurance.

To find out more about Gem Identification from AnchorCert Gem Lab, please visit our website www.anchorcert.co.uk or get in touch with the team today on 0871 423 7922.