ESSENEITE

    Class : Silicates
    Subclass : Inosilicates
    Crystal system : Monoclinic
    Chemistry : CaFeAlSiO6
    Rarity : Very rare

Esseneite (or essenite) is a very rare pyroxene that is found in molten sediments following the spontaneous and natural combustion of coal veins. It is also found in neoformation in foundry slag. It was named in honor of Professor of Geology Eric Essene of the University of Michigan. Esseneite forms prismatic grains measuring 8 mm maximum with a dark reddish brown hue.

Main photo : Esseneite from slag of Lapanouse-de-Sévérac, Rodez, Aveyron, France © Pascal Chollet

Esseneite in the World

This mineral is only known from two coal mines : Reno Junction near Gillette (Wyoming) where the 8 mm grains come from and Kopeïsk (Southern Urals, Russia) as well as in a few meteorites.

Esseneite in France

In France, esseneite is known around the coal mine of St-Maime (Alpes-de-Haute-Provence) as well as in the slags of Lapanouse (Aveyron).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fake listed for this mineral species.


Hardness : 6
Density : 3.54
Fracture : Undetermined
Streak : White

TP : Transparent
RI : 1.795 to 1.825
Birefringence : 0.030
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : -


Magnetism : None
Radioactivity : None