1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Conchoidal, Gems, Sixth Edition (2006)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), (e.g. graphite).
1.6 Cleavage
Perfect on {001}, less perfect on {010}, intersecting at near 90°; distinct on {110}
Distinct on {001} and {110}, indistinct on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)1-2Si3-2O8
Pb 2(CO 3)Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references