Splintery, Granular, Splintery, Granular, Gemstones (2009)
Brittle, Metallic, Brittle, Metallic
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references
CaZnSiO 4 · H 2OAnthony et al , Handbook of mineralogy (2001)