Yukonite

General Information: Chemical Formula:Ca7Fe+++11(AsO4)9O10·24.3(H2O) Composition:(Molecular Weight = 2,742.90 gm)Calcium 10.23 % CaIron 22.40 % FeArsenic 24.58 % AsHydrogen 1.79 % H Oxygen 41.01 % O  Empirical Formula: Ca7Fe3+11(AsO4)9O10·24.3(H2O) Locality:Tagish Lake, Yukon Territory, Canada. Name Origin:Named for the locality.Physical Properties: Color:brownish black, dark red, or reddish brown. Density:2.8 Habits:Amorphous - No crystalline form or imitative shape., , Hardness:2-3 - Gypsum-Calcite Luminescence:Non-fluorescent. Luster:Resinous Streak:light brownMore details...

Ca2Fe3(AsO4)4(OH) 12(H2O)