Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.355-3.4334.95-5.0
1
7.18
👆🏻
Fracture
Uneven
Uneven
Cleavage
{???} Good, {???} Good
Imperfect to indistinct on {10 1 0}, parting on {0001}
Mohs Hardness
-99994-5
2
10
👆🏻
Chemical Composition
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)
(Ce,La)(CO 3)FMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references