Subconchoidal, Uneven, Conchoidal, Uneven
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)