Subconchoidal, Uneven, Conchoidal, Uneven
Uneven, UnevenArthur Thomas, Gemstones (2009)
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Pb 26Ag 10Cu 24Cl 62(OH) 48 · 3H 2OWalter Schumann , Gemstones of the world (2001) More from other references