Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
SiO 2 · nH 2OGemdat.org , Management Team (2012)
Ca 5(PO 4) 3FAnthony et al , Handbook of mineralogy (2001)