Grossular Garnet

Studio Fluorescent Lighting: Rough and cut grossular garnets from Kenya

Overview

Grossular garnet is one of the major types of garnet and is composed of a calcium-aluminum silicate.  There are a number of “species” of garnet, all of which tend to be found in mixed states; that is, rarely is a garnet crystal 100% one species. Most grossular garnet contains traces of andradite or other garnet species. Grossular garnets have a relatively high refractive index (1.731-1.754), giving cut stones a wonderful brilliance.  They come in a range of colors from deep greens to yellow-greens, golden yellows and completely colorless “leucogarnets.”  With a Mohs hardness of  7.0-7.5, its a relatively durable gemstone and suitable for use in a variety of jewelry.

Named Species/Varieties

There are several varieties of grossular garnet sold in the trade.  Deep brownish-orange grossular is often referred to as “hessonite;” deep green grossular garnets are known as “Tsavorite” and lighter greens as “Merelani Mint Garnet.”  The deep green Tsavorites command the highest price premium, and demand in recent years has caused the price of fine Tsavorites to rise considerably.

Where is it found

Grossular garnets are found in a wide variety of locations around the globe.  Major economic deposits are found in Kenya and Tanzania where Tsavorite and Merelani Mint garnets are both found.  Minor deposits are found in Canada and the United States, Siberia and Sri Lanka.

Treatments

Grossular garnets are not typically treated.

Use in jewelry

The brilliance and hardness of grossular garnet make it a great choice for use in jewelry.

Buy grossular garnets

You can look at my current inventory of loose grossular garnets here: http://www.earthstreasury.com/product-category/gemstones/garnet/grossular-garnet/

You can see my current inventory of Tsavorite and Merelani Mint garnets here: http://www.earthstreasury.com/product-category/gemstones/garnet/green-garnet/