Adularia (Moonstone) is a semi-precious, clear, transparent, glassy form of potash felspar which is found mainly in the crevices of crystalline schists and gneisses, often in beutifully perfect crystals. It has sometimes a pearly, opalescent reflection or play of colours. It derives its name from Adula, a mountain peak in Switzerland, where fine specimens are found.
No related terms.