UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001), Uneven
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001), Brittle, Metallic
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)
BeAlSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references