The minerals of the earth provide priceless treasure - however, few minerals are used just as they come from the ground, most require some changes to make them useful. Gemstones must be cut and polished before their true beauty shows.
Alloy - a mixture of two or more metals or a mixture of a metal with another substance. 925 sterling silver is actually a combination of 92.5% silver and an alloy of 7.5% of copper or another metal. The addition of the alloy helps to enhance your silver jewelry and does not in any way detract from its quality.
Cabochon - a gem cut so that the stone has a smooth rounded top, a flat bottom and no facets. The usual shape for cabochons are round or oval, though they may be found in other distictive shapes.
Carat - the unit of weight for gems. One carat equals 0.2 grams (0.007 ounces) or 200 milligrams.
Clarity - a measure of how clear and free of flaws a gemstone is.
Cut - the shape in which a gem is finished. Common cuts include the round, marquis, pear, heart and emerald and cushion-cut. A person who cuts and polishes gemstones is called a lapidary. There are two basic types of finished stones: faceted stones and cabachons.
Facet - (noun) one of the small, flat, polished surfaces on a cut gem.
Facet - (verb) to cut or grind facets on a gemstone.
Gem - a beautiful, rare and durable mineral that has been cut and polished for use as a jewel.
Girdle - the wides section of a faceted stone. The top and bottom facets come together at the girdle.
Luster - the way the surface of a stone looks when it reflects light.
Minerals - solid materials that naturally occur on Earth, other planets, moons and meteorites. There are approximately 3,000 different kinds of minerals on Earth, but only about a hundred are common.
Vitreous - have a glassy luster.
Cushion Cut Faceted Green Amethyst Gem Bezel Set in 925 Sterling Silver
For more information on minerals visit:
Minerals - Wikipedia