What is Lapis Lazuli?
The beautiful blues in paintings from the Renaissance are thanks to the blue of lapis lazuli, the blue rock loved by the ancients from Mesopotamia, Egypt, Persia, Greece and Rome. The name is international, from the Latin, lapis, which means stone, and from the Arabic, azul, which means blue. Lapis lazuli is a semi-precious stone valued for its deep blue color. The source of the pigment is not a mineral but a rock colored by lazurite. In addition to the lazurite minerals in lapis lazuli, small amounts of white calcite and of pyrite crystals are usually present. Lapis lazuli is still mined in Afghanistan and Chile. Because lapis is a rock of varying composition, its physical properties are variable. Lapis lazuli is somewhat porous and should be protected from chemicals and solvents. It usually occurs in crystalline limestones and is a product of contact metamorphism. Lapis on Mohs’ hardness scale is 5.5.
