Lapis lazuli is a rock composed of the feldspathoid mineral lazurite, which gives it a strikingly blue color. Frequent secondary components are calcite, sodalite and pyrite. It is formed by contact metamorphism in marbles and limestones, near igneous intrusions. Well developed crystals as here seen are rare. Marble is the most common host-rock as also in this specimen. Lapis lazuli is a semi-precious stone widely used in jewelry, and has been prized since antiquity. The richest occurrences are in the Badakhshan province of Afghanistan, where lapis has been mined for 6, 500 years; jewelry containing it has been found at ancient Egyptian sites. For scale see pencil tip