Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
{111} Indistinct, {111} Indistinct, {111} Indistinct
Fe2+ Al 2O 4Gemdat.org , Management Team (2012)