Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
1.792.58-2.74
1
7.18
👆🏻
Fracture
Irregular/uneven
ConchoidalWalter Schumann, Splintery
Cleavage
Perfect on {10bar10}
{100} Distinct, {110} Distinct
Mohs Hardness
2.55.5-6
2
10
👆🏻
Chemical Composition
Ca6(Al,Si)2(SO4)2B(OH)4(OH,O)12•26(H2O)
Na 4Al 3Si 9O 24Cl to Ca 4Al 6Si 6O 24(CO 3,SO 4)Walter Schumann , Gemstones of the world (2001) More from other references