Uneven, Subconchoidal, Uneven, Subconchoidal, Conchoidal, Brittle
Gemstones of the world (2001), Difficult, Splintery
NaAlSi 2O 6 · H 2OMichael OâDonoghue , Gems, Sixth edition (2006) More from other references
Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2 Jadeite: NaAlSi2O6