Julgoldite-(Fe )

General Information: Chemical Formula:Ca2Fe++(Fe+++,Al)2(SiO4)(Si2O7)(OH)2·(H2O) Composition:(Molecular Weight = 545.54 gm)Calcium 14.69 % CaAluminum 2.47 % AlIron 25.59 % FeSilicon 15.44 % SiHydrogen 0.74 % H Oxygen 41.06 % O  Empirical Formula: Ca2Fe2+Fe3+1.5Al0.5(SiO4)(Si2O7)(OH)2·(H2O) IMA Status:Approved IMA 1968 Name Origin:Named in 1971 by Moore for Julian Royce Goldsmith (1918-), American geochemist, University of Chicago.Physical Properties: Color:black, greenish black, or green. Density:3.602 Diaphaniety:Translucent Hardness:4.5 - Between Fluorite and Apatite Luster:Sub MetallicMore details...

General Information: Chemical Formula:Ca2Fe+++(Fe+++,Al)2(SiO4)(Si2O7)(O,OH)2·(H2O) Composition:(Molecular Weight = 543.53 gm)Calcium 14.75 % CaAluminum 2.48 % AlIron 25.69 % FeSilicon 15.50 % SiHydrogen 0.37 % H Oxygen 41.21 % O  Empirical Formula: Ca2Fe3+2.5Al0.5(SiO4)(Si2O7)O2·(H2O) Environment:Fracture filling in hematite-magnetite ore from the Amerika stope at Langban. IMA Status:Not IMA Approved Locality:Langban, Varmland, Sweden. Name Origin:Named in 1971 by Moore for Julian Royce Goldsmith (1918-), American geochemist, University of Chicago.Physical Properties: Cleavage:[100] Good Color:deep lustrous black or greenish olive. Density:3.6 Habits:Bladed - Aggregates of thin lath-like crystals (e.g. kyanite)., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Hardness:4.5 - Between Fluorite and Apatite Luster:Sub MetallicMore details...