Typically sourced from Italy (Volterra), Egypt, and Spain, this is a commercial term referring to a compact, fine-grained variety of gypsum—and sometimes also compact calcite (“calcareous alabaster” or “Egyptian alabaster”) — formed by evaporitic precipitation in sedimentary basins. It has very low hardness (2 on the Mohs scale for gypsum), characteristic translucency, and a color ranging from pure white to colored veins.

A prized sculptural material since ancient times (Egyptian canopic jars, Italian statuary from Volterra); widely used for decorative objects, lamps, and home furnishings; soft and easy to work with but delicate and sensitive to water.