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, Uneven, Brittle
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
1.6 Cleavage
Imperfect on {001}, indistinct on {011}
Good in three directions
1.7 Mohs Hardness
1.8 Chemical Composition
Not Available
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references