1 Physical Properties
1.1 Tenacity
1.2 Solubility
Decomposed by acids
Soluble
1.3 Durability
Not Available
Not Available
1.5 Specific Gravity
2.4 Fracture
Not Available
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
2.5 Cleavage
Perfect on {010}
Poor to good on (001)
2.6 Mohs Hardness
2.12 Chemical Composition
(K,Na)3Cu20Al3Si29O76(OH)16•~8(H2O)
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.