How do I identify Stilpnomelane?

Stilpnomelane can be identified by its hardness of 3 - 4 on the Mohs scale, Red color. Look for these key characteristics when examining specimens.

What color is Stilpnomelane?

Stilpnomelane typically appears in Red, brown, black, dark green, dark reddish brown, golden brown. Color can vary depending on impurities and formation conditions.

How hard is Stilpnomelane?

Stilpnomelane has a hardness of 3 - 4 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Stilpnomelane

A variety of Minerals

What is Stilpnomelane?

Stilpnomelane is a phyllosilicate mineral. It has the formula K(Fe,Mg,Fe)8(Si,Al)12(O,OH)27·n(H2O). Stilpnomelane occurs associated with banded iron formations. It is a metamorphic mineral associated with the blueschist and greenschist facies. It was first described in 1827 for an occurrence in Moravia in the Czech Republic. The name is derived from the Greek stilpnos for shining, and melanos for black.

Stilpnomelane Market Value Calculator

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

Stilpnomelane Localities Map

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

Map preview

North ZoneCentral RidgeSouth Basin

Quick Facts

Physical Properties

Color: Red, brown, black, dark green, dark reddish brown, golden brown
Hardness (Mohs): 3 - 4
Density: 2.667 g/cm³
Streak: White, grey

Chemical Properties

Chemical Formula: (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O The ratio of ferric vs. ferrous iron varies greatly. An ideal end-member "ferrostilpnomelane" can be represented by K5Fe482+(Si63Al9)O165(OH)48.12H2O. An ideal end-member "ferristilpnomelane" (which is thought to result from oxidation after primary crystallization) can be represented by K5Fe483+(Si63Al9)O216.36H2O. Note that neither end-member composition has been reported yet.
Elements: Al, Ca, Fe, H, K, Mg, Na, O, Si