1 Physical Properties
1.1 Tenacity
1.2 Solubility
Partly soluble in HCl.
Soluble
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
1.6 Cleavage
{100} perfect; {110} and {1 1 0} good; {010} poor
Imperfect on {110}
1.7 Mohs Hardness
1.8 Chemical Composition
(Ca,Mn2+ )Si 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.