1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Granular
1.6 Cleavage
Perfect on {110}, poor on {101}, {001} rare
Not Available
1.7 Mohs Hardness
1.8 Chemical Composition
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2(Mg,Fe)Al 2(SiO 4)(Si 2O 7)(OH) 2 · H 2O)Arthur Thomas , Gemstones (2009)