|Finest Red Garnet
If you look at gemological information on garnet, you'll see that there are six different members of the garnet group; pyrope, almandite, spessartite, grossularite, andradite and uvarovite. All of these have a similar crystal structure, but they vary slightly in their chemical composition.
In the real world, natural garnets rarely match the specifications for these types exactly. In fact varietal names have been given to some garnets of intermediate composition. For example, the garnet with a composition halfway between spessartite and pyrope is known as malaia. Another example is rhodolite garnet, which has a chemical composition averaging a 2:1 mixture of pyrope to almandite.
Rhodolite garnet is interesting not only for its chemical composition, but also for its unique color. It is a red garnet, but is very different from the familiar deep brownish-red of ordinary red garnet. Rhodolite's name comes from the Greek rhodon meaning rose, and its color ranges from rose red to raspberry red, purple-red or purple-pink.
One of the interesting facts about rhodolite garnet is that it was first discovered in the United States, in the state of North Carolina, around 1898. Even more interesting, it was discovered by mineralogist W.E. Hidden, who also discovered hiddenite, the green variety of spodumene that bears his name.
North Carolina is no longer a significant source for rhodolite. Today the major commercial deposits are in Sri Lanka, Brazil, Zimbabwe, Tanzania, Kenya, Mozambique, Madagascar and India.
Fine rhodolite from Mozambique and Tanzania has excellent color saturation and clarity. We've cut dozens of pieces around 10 carats and a few pieces over 30 carats, including one remarkable 96 carat gem.
Since garnet has a hardness of 7 to 7.5 on the Mohs scale and indistinct cleavage, it is a durable gemstone that is suitable for all kinds of jewelry. Rhodolite garnet has a high refractive index. In fact, the refractive index of rhodolite garnet is slightly higher than sapphire and ruby, so it has excellent brilliance. Rhodolite is one of the more expensive garnets, falling between common red garnet and spessartite in price. Additionally rhodolite, like other garnets, is always untreated. So given its stunning color and good gemological properties, rhodolite is a gemstone of superb value.
- First Published: March-27-2008
- Last Updated: June-17-2014
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