ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Subconchoidal, UnevenArthur Thomas, Fibrous
Be3Al2SiO6
Al 3(PO 4) 2(OH,F) 3 · 5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references