January Birthstone – Garnet

From the Archives – First Published January 7, 2015 in The Ponca City News Midweek

Ever wonder about birthstones?  What they are and why they came to be associated with certain properties?  According to the American Gem Society, the history associated with wearing birthstones goes back to the Breastplate worn by Aaron representing the 12 Tribes of Israel.  However, other sources indicate that the tradition of wearing birthstones is related to the 12 signs of the Zodiac.  Whatever the source of the tradition, there are numerous legends and myths about each birthstone’s particular healing powers and various associations.  Over time the list of which stone corresponds with which month has changed.  The current list dates back to 1912, and the stone for January is garnet.

Garnet is supposed to signify eternal friendship, passion, loyalty, success, and faith.  The traditional garnet is generally red and is associated with the myth of Persephone, as the red garnet has the color of a pomegranate seed which is what Hades presented to Persephone.  The name garnet comes from the Latin “granatus” meaning seed.

Garnets actually come in a variety of colors: the traditional red (almandine), a red to orange (grossular), red and pink (pyrope), green-brown (spessartite), brown/black (andradite), and emerald green (uvarovite). The color of any gemstone is a result of the way the stone absorbs light.  The color usually is the result of a particular impurity in the crystal structure of the material that makes up the stone.  Garnets are made from calcium aluminum silicate (Ca3Al2 (SiO4)3) and are considered silicates.  The colors arise from the impurities in the calcium aluminum silicate crystal.  The red of the traditional almandine garnet comes from iron, while the green color of the uvarovite comes from chromium.  To get the orange color a bit of manganese gets mixed in with the iron.  Thus, the color of the garnet comes from the “flaws” in the crystal, those substitutions of the other metals for the calcium or the aluminum in the crystal structure.

This gemstone is found in metamorphic rocks, rocks that are subjected to high heat (300 degrees to 400 degrees Fahrenheit) and pressures 1500 BAR or about 22,000 psi.  These types of conditions are generally associated with the formation of granite and volcanic rocks.  The current source for most garnets is Africa (Zimbabwe, Tanzania, Kenya, Mozambique and Madagascar), Sri Lanka and India.  Although, pyrope garnets have been found in Brazil, Australia, United States, Mexico and Myanmar, while almandine garnets have been found in Alaska, Brazil and Greenland.

In addition to being pretty and worn as part of jewelry, garnets have a variety of uses.  The gemstone has a rating of 6.5 to 7.5 on the hardness scale (depending on the specific type of garnet).  This means it has about the same hardness as quartz.  Only topaz, corundum and diamonds are harder.  Making garnets an excellent source for abrasive materials.  According to Geology.com, in 2012 75% of the industrial use of garnets in the United States was for abrasive activities such as waterjet cutting, blasting and as an abrasive powder.  The other use of garnet is in water filtration.  Garnets are also used as watch gears, and in semiconductor manufacturing.

There are numerous traditions associated with garnet like that of Noah using a garnet lantern to light the way in the dark or of Hades using the garnet as a sign of fidelity, loyalty and faith.  These properties seem to have some physical basis – the stone is strong, and durable.  It has a vitreous luster, i.e. it has reflective properties. And, is not artificially enhanced in any way.

Image Credit: Used under license from 123RF – Luchschen

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