1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Conchoidal, Conchoidal, Brittle
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
1.6 Cleavage
Perfect on {001}, good on {110}
None, may show partings on {0001} and {10 1 1}
1.7 Mohs Hardness
1.8 Chemical Composition
KNa 4Ca 4Si 8O 18(CO 3) 4(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Fe 2O 3Arthur Thomas , Gemstones (2009)