The composition of scapolite is similar to that of plagioclase, but it contains additional anions of Cl−, (CO3)2− and (SO4)2−. Scapolite includes calcium-rich meionite and sodium-rich marialite. It has a tetragonal crystal system, the crystals are columnar, and the aggregates are granular and platy. It is colourless, white, grey, light blue, light green, light yellow, light brown, pink or violet in colour. It has transparent to translucent diaphaneity, a vitreous to pearly or resinous lustre, a specific gravity of 2.50–2.78, and a Mohs hardness of 5.5–6. It is common in skarn deposits and forms with garnet and diopside. It also forms in gneiss and amphibolite.