Subconchoidal, Uneven, Conchoidal, Uneven
Conchoidal, Conchoidal, Gemstones of the world (2001)
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001) More from other references