1 Physical Properties
1.1 Tenacity
1.4 Solubility
1.5 Durability
Not Available
Not Available
1.6 Specific Gravity
1.7 Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001)
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
1.8 Cleavage
Not Available
Imperfect on {110}
1.9 Mohs Hardness
1.12 Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.