Roscoelite is a green mineral from the mica group that contains vanadium.

The mineral was named after Henry Enfield Roscoe who first produced vanadium metal.

[3] Two kinds of mineral deposits contain roscoelite, either gold-silver-tellurium low temperature epithermal deposits where it occurs along with quartz, fluorite, pyrite and carbonates, or oxidized low temperature uranium-vanadium ores in sedimentary rocks, where it occurs with corvusite, hewettite, carnotite and tyuyamunite.

[5] The mineral has been found in numerous places in US, Australia, Japan, Gabon, Fiji, New Guinea[6] and Czech Republic.

In the United States, it was the principal vanadium ore mineral at the mines at Placerville, Colorado.