Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001)
Good to perfect_usually N/A
{100} Perfect, {001} Perfect
CuAl6(PO4)4(OH)8 • 4H2O
Na(Mn2+ ,Ca) 2Si 3O 8(OH)Michael OâDonoghue , Gems, Sixth Edition (2006)