Friday, March 16, 2012

Gemstone of the Week: Lapis Lazuli

(Lapis Lazuli sample from Gemstones-Guide.com)

Images of Lapis Lazuli

Lapis Lazuli is a gorgeous blue gemstone.  It is the anniversary stone for the 9th anniversary.  The interesting thing will Lapis Lazuli, is that it is not a single mineral.  It is, in fact, comprised of Lazurite, some Calcite, Pyrite, and sometimes some other minerals.  Lapis Lazuli has been mined for centuries.  While its primary use has been adornment the Ancient Egyptians, Greeks, and Romans would also grind it up to use for eye shadow, medicine, and a paint pigment known as ultramarine. The most valued Lapis Lazuli is that which has a rice blue-violet colour with little or no Calcite.  

Often, Lapis will be dyed to minimize the noticebility of the Calcite in the Lapis, however this dye is not always stable and may rub off unless sealed.  As with any stone, if the seller knows it has been treated they are supposed to disclose this, however, they don't always or may not even know if it has been treated or not.  If you would like to test whether the colour on your Lapis has been dye-treated or not, you can often find out by rubbing the Lapis with a piece of cotton that has been diped in finger-nail polish remover or alcohol.  If you do do this to test the colour of your Lapis, try to do it in an inconspicuous spot.

Much of the Lapis Lazuli that is found is mined in Afghanistan, but it can also be found in Chili.  However, the "Lapis" that comes out of Germany and Switzerland is not actually Lapis Lazuli at all but blue-dyed Jasper that is often used as imitation Lapis Lazuli.