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
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
1.6 Cleavage
Perfect on {001}, good on {110}
None observed
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)
Al 6B 5O 15(F,OH) 3Ulrich Henn and Claudio C.