1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Fibrous, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), (e.g. graphite).
1.6 Cleavage
Distinct on {100}, poor on {110}; parting on {001}
Distinct on {001} and {110}, indistinct on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
AlAl6O3BSi3O18
Pb 2(CO 3)Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references