How do I identify Roscoelite?

Roscoelite can be identified by its hardness of 2.5 on the Mohs scale, Brown color. Look for these key characteristics when examining specimens.

What color is Roscoelite?

Roscoelite typically appears in Brown, dark green to black. Color can vary depending on impurities and formation conditions.

How hard is Roscoelite?

Roscoelite has a hardness of 2.5 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Roscoelite

A variety of Minerals

What is Roscoelite?

Roscoelite is a green mineral from the mica group that contains vanadium. The chemical formula is K(V, Al, Mg)2AlSi3O10(OH)2. Crystals of roscoelite take on the monoclinic form, and are from the 2/m point group. The appearance is semi transparent to translucent coloured olive brown to green brown. The lustre is pearly. The mineral shows pleochroism with X showing green-brown, and Y and Z axes showing olive-green colour. The mineral was named after Henry Enfield Roscoe who first produced vanadium metal.

Roscoelite Market Value Calculator

Estimate the market value of Roscoelite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Roscoelite Localities Map

See where Roscoelite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Roscoelite

It is soft and the density is 2.93±0.01. The unit cell has dimensions a = 526 pm b = 909 pm c = 1025 pm, with an angle between axes of β=101.0°. The tetrahedral cation-oxygen atom distance is 164.1 pm, The distance from the cation to the oxygen in the octahedral plan is 202 pm.

Formation of Roscoelite

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. Roecoelite is considered a gangue mineral of no value when found with gold. However it has also been used as a vanadium ore. In the Mt. Kare mine in New Guinea the mineral occurs with gold and is an important maker of gold deposits. The temperature of the geothermal fluid that deposited the roscoelite was from 127 to 167 °C (261 to 333 °F). The fluid contained a high level of salt and also contained carbon dioxide, methane, carbonyl sulfide and other minor amounts of rock forming elements.