Minerals identify

Know how to recognize them

Hercynite

Oxide mineral,spinel group,spinel structural group

Hercynite is a spinel with the formula FeAl2O4.

It occurs in high-grade metamorphosed iron rich argillaceous and ultramafic. Due to its hardness it also is found in placers

It was first described in 1847 and its name originates from the Latin name for the Harz

Hercynite is a spinel of regular symmetry and normal cation distribution, but some disorder occurs in its structure. It consists of ferrous (Fe2+) ions and aluminium ions (Al3+), however some ferric ions (Fe3+) may be located in the structure of hercynite.

Identification

Color of mineral

Black

Mohs scale ( mineral hardness )

7.5

The streak

Green

Density ( specific gravity )

1.8

Luster ( interacts light )

Vitreous

Crystal ( diaphaneity )

Isometric