SCRATCH: White, light blue.
BRIGHTNESS: Vitreous, smeary in fractures
EXFOLIATION- FRACTURE: Perfect to uneven fracture. Conchoid.
CRYSTALLIZATION: Well-formed crystals, arranged in fracture planes.
Semiprecious stone composed of minerals lazurite, calcium silicate (provides the blue color), wollastonite and calcite (gray and whitish veining) and pyrite (golden reflections). It comes from Afghanistan and northern Chile. Much appreciated since Antiquity, in the Middle Ages it was worth more than gold. Unlike similar stones such as azurite, it does not effervesce in contact with hydrochloric acid.