Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
{0001} good, {10 1 0} parting
{100} perfect; {110} and {1 1 0} good; {010} poor
(Ca,Ce)(Al,Ti,Mg)12O19
(Ca,Mn2+ )Si 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references