How do I identify Jacobsite?

Jacobsite can be identified by its hardness of 5.5 - 6.5 on the Mohs scale, Black color. Look for these key characteristics when examining specimens.

What color is Jacobsite?

Jacobsite typically appears in Black, gray in reflected light. Color can vary depending on impurities and formation conditions.

How hard is Jacobsite?

Jacobsite has a hardness of 5.5 - 6.5 on the Mohs scale. This gives it moderate hardness.

How to Identify Jacobsite | Properties, Meaning & Uses

What is Jacobsite?

Jacobsite is a manganese iron oxide mineral. It is in the spinel group and forms a solid solution series with magnetite. The chemical formula is MnFe2O4 or with oxidation states and substitutions: (Mn,Fe,Mg)(Fe,Mn)2O4. It occurs as a primary phase or as alteration of other manganese minerals during metamorphism of manganese deposits. Typical associated minerals include hausmannite, galaxite, braunite, pyrolusite, coronadite, hematite and magnetite. It is a ferrimagnetic substance, which is weakly attracted by a magnet. It was first described in 1869 and named for the Jakobsberg Mine, Nordmark, Filipstad, Värmland, Sweden.

Jacobsite Market Value Calculator

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

Jacobsite Localities Map

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