Angelite

ANGELIT is a trade name for the variety ANHYDRITE, most often light-blue or blue-gray to gray. It comes from Peru and is one of the favorite semi-precious stones.
As such, anhydrite (CaSO4 - calcium sulfate) is a rhombic mineral. The name comes from the Greek anhydros - anhydrous, as unlike gypsum does not contain water. Natural occurrence is in the vast majority of sedimentary origin, belongs to the so-called evapority (as well as gypsum, halite, sylvin and others). Hydrothermal - forms tailings in ore veins, post-volcanic - from volcanic gases (fumaroles) and magmatic. They form crystals, fibrous, spherical, fine-grained to whole aggregates, pseudomorphoses. The crystals have the shape of prismatic tables (the areas are grooved), twins.