Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
[010] Perfect, [100] Distinct, [011] Distinct
Amethyst, Clear Quartz, Smoky Quartz, Cacoxenite, Rutile, Geothite, Lepidocrocite
{001} Perfect, {110} Distinct, {101} Distinct
Be 4Si 2O 7(OH) 2Anthony et al , Handbook of mineralogy (2001)