Coloured scanning electron micrograph (SEM) of fractured lapis lazuli. Lapis lazuli is a rock whose most important mineral component is lazurite, a feldspathoid silicate mineral. Most lapis lazuli also contains calcite sodalite and pyrite. Lapis takes an excellent polish and can be made into jewelry, carvings, boxes, mosaics, ornaments, small statues, and vases. It was also ground and processed to make the pigment ultramarine, widely used during the Renaissance in frescoes and oil painting. Its usage as a pigment in oil paint largely ended in the early 19th century when a chemically identical synthetic variety became available. Magnification: x4000 at 10cm high.