SOFFA 05 / MATERIALS, English edition

LAPIS LAZULI IS NOT A MINERAL BUT A ROCK (SEMI-PRECIOUS STONE) WHICH CONSISTS OF 3 MAIN MINERALS: CALCITE (CALCIUM CARBONATE CaCO3), PYRITE (IRON DISULFIDE FeS2) AND LAZURITE (TECTOSILICATE MINERAL WITH SULFATE, SULFUR AND CHLORIDE (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2). THE ULTRAMARINE COLOUR OF LAPIS IS CAUSED BY THE PRESENCE OF LAZURITE. LAZURITE IS A TECTOSILICATE MINERAL WITH SULFATE, SULFUR AND CHLORIDE AND ONLY RARELY IT CREATES INDIVIDUAL CRYSTALS (IT EXISTS MAINLY AS A PART OF MARBLE). LAPIS LAZULI IS VERY POPULAR IN JEWELLERY MAKING AS WELL AS IN INTERIOR DECORATING. BEING A DECORATIVE STONE AND A SOURCE OF BLUE PIGMENT (ULTRAMARINE) IT WAS USED ALREADY IN ANCIENT EGYPT AND MESOPOTAMIA. WHILE LINES OF CALCITE AND GOLDEN CRYSTALS CONTAINED IN LAPIS LAZULI ARE NOT CONSIDERED A FLAW. Lapis lazuli – a stone block and a necklace; both Mineralia