Tenacity
Brittle
-
Solubility
H₂SO₄
-
Durability
-
-
Specific Gravity
2.74-3.002.90-3.10
1
7.18
👆🏻
Fracture
Uneven
Splintery, Granular
Cleavage
Distinct on {0001} imperfect on {11 2 0}
None
Mohs Hardness
5-5.56-6.5
2
10
👆🏻
Chemical Composition
Na 4(Ca,Ce) 2(Fe,Mn,Y)ZrSi 8O 22(OH,Cl) 2Ulrich Henn and Claudio C.
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references