Lithiophilite: Gemstone Information
Lithiophilite is Li(Mn2,Fe2)PO4, forming a series with triphylite (q.v.),and forms transparent to translucent clove brown to greenish brown to yellow sharply terminated crystals of the orthorhombic system with one direction of perfect cleavage, hardness 4–5, SG 3.4–3.5. The RI for the alpha, beta and gamma rays is 1.663–1.696, 1.667–1.700 and 1.674–1.702,biaxial positive with birefringence 0.005. Lithiophilite occurs as a latestage mineral in some complex granite pegmatites. Gem-quality material has come from Brazil.