Splintery, Granular, Splintery, Granular, Gemstones (2009)
Uneven, Subconchoidal, Uneven, Subconchoidal, Conchoidal, Brittle
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references
NaAlSi 2O 6 · H 2OMichael OâDonoghue , Gems, Sixth edition (2006) More from other references