Triplite: Gemstones Information

Triplite is (Mn2,Fe2,Mg,Ca)2(PO4)(F,OH) and crystals occur in a number of indistinct forms or as masses which are translucent to opaque dark red to brown, or black if altered. The crystal system is monoclinic, the hardness 5–5.5 and the SG 3.85–3.94. The RI for the alpha, beta and gamma rays is 1.643–1.684, 1.647–1.693, 1.668–1.703,biaxial positive with birefringence 0.020. Triplite occurs as a principal primary phosphate in complex-zoned granite pegmatites or in hydrothermal tin veins. Ornamental material has been reported from Brazil.