Leifite: Gemstone Information

Leifite is Na2(Si,Al,Be)7(O,OH,F)14 and forms transparent to translucent light yellow, light violet or colourless acicular, deeply striated hexagonal prismatic crystals of the trigonal system with hardness 6 and SG 2.57.The RI for the ordinary and extraordinary rays is 1.515 and 1.519, uniaxial positive, birefringence 0.004. A green fluorescence under SWUV has been reported. Leifite occurs in association with an intrusive alkalic gabbro-syenite complex at Mt Saint Hilaire, Quebec, Canada.