Tenacity
Brittle
Brittle
Solubility
-
H₂SO₄
Durability
-
-
Specific Gravity
2.33-2.372.74-3.00
1
7.18
👆🏻
Fracture
Uneven
Uneven
Cleavage
Perfect on {001}, imperfect on {110}
Distinct on {0001} imperfect on {11 2 0}
Mohs Hardness
4.5-55-5.5
2
10
👆🏻
Chemical Composition
(K,Na)Ca4Si8O20(F,OH)•8(H2O)
Na 4(Ca,Ce) 2(Fe,Mn,Y)ZrSi 8O 22(OH,Cl) 2Ulrich Henn and Claudio C.