Lapis lazuli is not a single mineral but a rock, a rich blue blend of lazurite with white calcite and glittering golden flecks of pyrite. Humans have treasured it for over 6,000 years. The mask of Tutankhamun is inlaid with it, and Renaissance painters ground it into ultramarine, once the most expensive pigment in the world. The finest lapis still comes from the Sar-e-Sang mines of Afghanistan, worked since ancient times, with more from Chile and Russia. The best colour is a deep, even royal blue with just a sprinkle of pyrite.
Lapis is on the softer side at 5 to 6 on the Mohs scale, so it will slowly dull in a hard-working ring but does beautifully in pendants, earrings and beads. It is cut as cabochons, beads and carvings. Dyeing is common in lower grades to even out the colour, and it should always be disclosed; a swipe with acetone on a hidden spot will lift dye but not natural colour. Avoid chemicals and ultrasonic cleaners, and simply wipe it with a soft, damp cloth.
Sodalite is literally one of the minerals inside lapis, and dumortierite is its most common look-alike.
