Semi Precious Gemstones

Precious gemstones are usually thought of as transparent stones: diamonds, and what are known as the colored stones-rubies, emeralds, sapphires, etc. All other gemstones full under the semi-precious label. They are usually translucent (some light passes through) or opaque (no light passes through). Semi-precious gemstones can be minerals, rocks (a conglomerate of several minerals), organic (such as Amber), or even a meteorite. Generally gemstones with a hardness of 7 or lower are considered semi-precious. Most semi-precious stones are cut into cabochons instead of facted. There is a huge array of stone materials that fall under this category. The copper gemstones: chrysocolla, malachite, azurite and more fall under the semi precious gems category. Turquoise, of course, is probably one of the best known semi-precious gemstones. But there is also Tiger's Eye and Rhodochrosite and common opal, and a whole lot more rarer and sometimes very expensive semi precious gems. Semi precious gemstones can be almost any color: red, black, blue, brown, yellow, even orange. And they come in multi colors too!

One very common group of semi-precious gemstones is the chalcedony family, which includes agates and jaspers. See my agate and jasper guide for a more complex description. A vast variety of agate stones and jasper stones are found all over the world in many colors and patterns. The quality of the cutting can play an important part in determining the value of a semi-precious gemstone. The cutter needs to know how to orient the stone to its best advantage, and how to get a good glassy polished finish.