Tenacity
Brittle
-
Solubility
-
insoluble
Durability
-
-
Specific Gravity
3.28-3.442.36
1
7.18
👆🏻
Fracture
Uneven, Splintery
Uneven, Subconchoidal, Fibrous
Cleavage
Perfect on {110}, intersecting at 56° and 124°; partings on {100} and {010}
[110] perfect, [101] good, [010] distinct
Mohs Hardness
5.0-6.03.5-4
2
10
👆🏻
Chemical Composition
Na2Fe2+3Fe3+2Si8O22(OH)2
Al 3(PO 4) 2(OH,F) 3 · 5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references