Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
SiO 2 · nH 2OGemdat.org , Management Team (2012)
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)