Description
Lapis lazuli is an opaque semi-precious stone with an intense azure blue color. It is not a mineral, but a rock, because it consists of more than one component. It is primarily mined in Afghanistan. The main component of lapis lazuli is lazurite (25% to 40%), a feldspar substitute with the chemical formula (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2. [1] Other important components are calcite (white), sodalite (blue), and pyrite (yellow – metallic luster). Furthermore, the minerals augite, diopside, enstatite, micas, hauynite, hornblende, geyerite (a sulfur-rich variety of lollingite), and nosean may also occur in lapis lazuli. Lapis lazuli is not particularly hard for a gemstone. On the Mohs scale, the hardness is 5.5, which means that the stone can easily be scratched by harder gemstones. It is therefore not advisable to store jewelry containing lapis lazuli together with harder gemstones. Alternative healers attribute spiritual power to lapis lazuli. Lapis lazuli is usually formed through contact metamorphosis in crystalline marble. Lapis lazuli has been known since antiquity. It was traded in the city of Ur as early as 4000 BC. It was one of the trade products of the trade between Sumer, Dilmun, and Meluhha. It was also very popular in ancient Egypt. For example, it was used for the death mask of Tutankhamun. There was so much demand for it throughout the Middle East that imitations were already being manufactured in the time of Christ, as early as the 13th century BC. From the city of Sidon, for example, cylinder seals are known of King Annipi and his father Adummu, which were given a dark blue color using cobalt salts. Lapis lazuli was also used in ground form as a blue dye (ultramarine), which was also very popular in Renaissance painting.
