1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Uneven
1.6 Cleavage
Good on {110}, poor on {100}
None observed
1.7 Mohs Hardness
1.8 Chemical Composition
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Na 3AlF 6Ulrich Henn and Claudio C.