1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Uneven
ConchoidalGemdat.org, Uneven
1.6 Cleavage
Good on {110}
{111} Indistinct, {111} Indistinct, {111} Indistinct
1.7 Mohs Hardness
1.8 Chemical Composition
Mg 3Al 6(Si,Al,B) 5O 21(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Fe2+ Al 2O 4Gemdat.org , Management Team (2012)