The Natural Colors of Garnet
January 2nd, 2010 by James L. Sweaney, CGA, FGA. GG
A Suite of Garnets
Yes, they are all garnets. The January birthstone is usually thought of as a dark red gemstone, but like the sapphire, garnet occurs in colors we don’t expect to see. In fact, garnets can be purple, red, orange, yellow, colorless or green, almost all the colors but true blue. There is even a garnet that changes color, like the alexandrite!
Garnets are actually a family of gems with six main “members”, all of which are silicate minerals that have similar chemistry and a similar crystal shape. Each member/type is a combination of two metal ions bound with oxygen to a silicate ion. Most garnets are mixtures of these various members, sort of like the genetic mixtures we see in living creatures.
Our suite contains examples of the four main garnet types used in jewelry, i.e. almandine, pyrope, grossular, and spessartine garnets. Over the next month, we’ll examine in more detail the wonderful garnet family, exploring it’s colors and the other characteristics that make it such a desirable gemstone. Keep your eye on the Mardon blog!
Tags: almandine, color change garnet, garnet, grossular, pyrope, spessartine
