Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
{001} Perfect, {110} Distinct, {101} Distinct
Be 4Si 2O 7(OH) 2Anthony et al , Handbook of mineralogy (2001)
{110} Perfect, {010} Indistinct
(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al) 2O 6Anthony et al , Handbook of mineralogy (2001)