1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.54-2.783.50-3.60
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
1.6 Cleavage
Good in three directions
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.