Uneven, Splintery, Conchoidal, Uneven, Splintery, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
SiO 2Arthur Thomas , Gemstones (2009)
Al 2SiO 5Arthur Thomas , Gemstones (2009)