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
Gemstones of the world (2001)
Conchoidal, Conchoidal, Brittle
1.6 Cleavage
Not Available
Perfect on {001}, good on {110}
1.7 Mohs Hardness
1.8 Chemical Composition
SiO 2Walter Schumann , Gemstones of the world (2001)
KNa 4Ca 4Si 8O 18(CO 3) 4(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)