Gems : Lapis Lazuli

Lapis Lazuli is a beautiful, deep blue stone, although its exact colour varies due to the proportions of minerals mixed within it. It has been known since ancient times, and the second part of its name comes from a Persian word, lazhward, meaning blue. (The Latin word lapis means stone.)
Its historical source was high in the Badakhshan mountains in north-eastern Afghanistan, where it has been worked for over 6,000 years. Opaque and slightly soft, lapis lazuli is almost always cut en cabochon, or as beads, rather than being facetted.
Some lapis, as it is often called, is a lighter or greenish blue and some a rich purple blue, almost black. The best colour is an intense deep blue. Ultramarine pigment used to be made from crushed lapis, and probably provides the best description of its most desirable colour. It usually also contains golden coloured flecks of pyrites, which normally increase its desirability, and are an indication of authenticity.