1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Uneven, Gems, Sixth Edition (2006)
Conchoidal, Conchoidal, Brittle
1.6 Cleavage
None, but may exhibit parting
Perfect on {001}, good on {110}
1.7 Mohs Hardness
1.8 Chemical Composition
Al 2 O 3
KNa 4Ca 4Si 8O 18(CO 3) 4(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)