Sunday, August 7, 2011

Garnet - Industrial Uses and January's Birthstone

Garnets may have received their name from the Latin word granatum as red garnets look so very much like the seeds of the pomegranate fruit. Recently, I learned that there are 15 species of garnets and that they can come in a variety of colors besides red. Garnets can be transparent to opaque. Garnets are found all around the world and mostly in metamorphic rock. Metamorphic rock is existing rock that is changed into a new rock by heat or by heat and pressure.

garnet

The Moh's Hardness Scale compares the scratch resistance between minerals. Friedrich Moh chose ten well known minerals and place them on a scale from softest and can be easily scratched to hardest and can scratch other minerals. Diamonds proudly hold the number ten spot as they are the hardest substance and are able to scratch. I remember my nana telling us young, very surprised girls that a genuine diamond can cut a mirror or put a very big scratch in one. Garnets rate between a 6 and 7.5 on the Moh's scale. Their hardness and durability have made garnets very useful and popular for industrial purposes. Garnets have been and continue to be used in sand paper, sandblasting tools, cleaning agents for drill pipes and well casings, grinding and polishing optical lenses to name a few.

GARNET

I did not know the serious industrial value of garnets until my older daughter returned from a day of panning for garnets with her grandma. They went to Sabino Canyon which is located in Coronado National Forest in Arizona, and spent five glorious hours sifting through buckets of sandy dirt looking for garnets. They were thrilled to find many small granular sized ones. They enjoyed the park guides who told them all about garnets and how they were used in various industries. Their small finds had to stay at the park but the experience and information learned will last a lifetime.

Besides having practical uses garnets have been sought after for centuries and highly desired in jewelry pieces. Bohemia is known for having spectacular garnets and pyrope garnets as big as hen eggs have been found there. Spessartine garnets can range from pale yellow, orange, to dark red. The almandine is the most common garnet and is used for abrasives and for gems. It is found in many places around the world. Andradite is known for having high color dispersion and makes exquisite gem jewelry from its topaz yellow to emerald green varieties. The rarest garnet is the uvarovite named for a Russia nobleman. It is brilliant green in color and seems to be hindered in crystal growth as most specimens do not get very large. The hessonite is reddish-brown and found in Sri Lanka, Vermont, Mexico, Canada, Scotland, and Italy. In ancient days Romans and Greeks carved cameos from hessonite. Gossular garnets are found in calcium rich metamorphic rocks and have color variations from colorless, white, pink, red, brown, black, and honey.

In 1912, the American National Association of Jewelers named the garnet as January's birthstone. The garnet is a hardy, useful, beautiful, valuable, and an interesting stone that inspires one to inventive places and brings pleasure in creative jewelry adornment. The garnet truly is a gem because it is a highly prized beloved stone.

Garnet - Industrial Uses and January's Birthstone

GARNET

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