Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Al 2SiO 5Arthur Thomas , Gemstones (2009)
3NaAlSi 3O 8 · NaClAnthony et al , Handbook of mineralogy (2001)