PYRITES

(Lat.), n. m. Pir(pu8r)-it(et)'ez(as). Gr.. irvpmjs. Fr., pyrite. Ger., Scliwefelkies, Pyrit, Feuerstein. A native iron disulphide, FeSj, occurring as regular crystals of a metallic lustre and a sp. gr. of 5'0, and generating sparks when rubbed with steel. It always contains a small percentage of arsenic. [B, 270 (a, 38;.] Arsenical p. P. occurring as a mixture of arseuic disulphide, trisulphide, and pent a sulphide. [B, 93 (a, 14).] Iron p. See P. Magnetic p. A compound of various proportions of ferric and ferrous sulphides, resembling bra in color and showing magnetic properties. [B, 3.] P. arsenical is micaceus. Orpiment. [B, 119.] [s. 366]