1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.3 Solubility
Not Available
Not Available
1.4 Durability
Not Available
Not Available
1.5 Specific Gravity
Not Available2.90-3.14
1
7.18
1.9 Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001)
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
1.10 Cleavage
Not Available
Imperfect; basal
1.11 Mohs Hardness
1.12 Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
(Be,Cs) 3Al 2Si 6O 18 · 0.5H 2OUlrich Henn and Claudio C.