Color

When judging gemstones, color is a term that encompasses three qualities: hue, saturation and masking. Each quality is important, and affects the overall look of the gem.

Hue is the main body color of the gem, such as purple amethyst or green tourmaline.

Saturation is the strength or purity of the hue. Aquamarines are usually lighter – less saturated – than garnets.

Masking is the lightness to darkness tone of the gem overall. Thai sapphires can be very dark, but the darkness is often due to a dark masking, not a saturated blue hue.

Precious/semi-precious gem

Precious and semi precious are old-fashioned terms that are slowly phasing out of the jewelry vocabulary. The term "precious" used to indicate ruby, sapphire and emerald, while the term "semi-precious" indicated every other type of colored gemstone.

Unfortunately a "precious" ruby can be worth $200 and a "semi-precious" tourmaline of the same size can be worth $5000. So the words start to lose their meaning when used in a real world scenario.

The term "colored gemstones" is the best description for all species of colored gems.

Carving

Carving a gemstone means to fashion it with concave surfaces, convex surfaces, flat planes, grooves, undercutting and relief, all of which create their own patterns of reflection. Carving may take the form of a fully three-dimensional sculpture or a more two dimensional intaglio/cameo.

Faceting

Faceting a gemstone means to fashion it with small flat planes. There is also concave faceting utilizing small curved planes.

There will be more definitions given in the Gemscapes blog in the future. Stay tuned!