1 Physical Properties
1.1 Tenacity
1.2 Solubility
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}
Good to perfect_usually N/A
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)
CuAl6(PO4)4(OH)8 • 4H2O