Goldmanite - Encyclopedia
Class : Silicates
Subclass : Nesosilicates
Crystal system : Cubic
Chemistry : Ca3V2(SiO4)3
Rarity : Very rare
Goldmanite is a very rare calcic garnet, usually dark green in color. It is a vanadium garnet belonging to the ougrandite series which forms a continuous solid solution with the grossular. Like most ougrandites, goldmanite is found in regional metamorphic and contact rocks of impure limestones, but also in magnetite skarns and vanadium sedimentary rocks. It was named in honor of Marcus Isaac Goldman, a specialist in sedimentary petrology at the US Geological Survey. Like all garnets, goldmanite occurs in isometric crystals, generally small dodecahedra.
Main photo : Goldmanite from Rybnícek, Pezinok, Slovakia © Lubos Hrdlovic
Goldmanite in the World
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 6 to 7
Density : 3.74 to 3.77
Fracture : Conchoidal
Streak : White
TP : Translucent to transparent
RI : 1.821
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None
Solubility : Hydrofluoric acid
Magnetism : NoneRadioactivity : None