1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.4 Durability
Not Available
Not Available
1.7 Specific Gravity
1.16 Fracture
Uneven
Uneven, UnevenArthur Thomas, Gemstones (2009)
1.17 Cleavage
None observed
perfect along [010] and [100]
1.18 Mohs Hardness
1.19 Chemical Composition
Na 3AlF 6Ulrich Henn and Claudio C.
Cu 5(SiO 3) 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references