How do I identify Oldhamite?

Oldhamite can be identified by its hardness of 4 on the Mohs scale, pale brown to dark brown color. Look for these key characteristics when examining specimens.

What color is Oldhamite?

Oldhamite typically appears in pale brown to dark brown. Color can vary depending on impurities and formation conditions.

How hard is Oldhamite?

Oldhamite has a hardness of 4 on the Mohs scale. This gives it moderate hardness.

Oldhamite

A variety of Minerals

What is Oldhamite?

Oldhamite is a calcium magnesium sulfide mineral with formula (Ca, Mg)S. Ferrous iron may also be present in the mineral resulting in the formula: (Ca,Mg,Fe)S. It is a pale to dark brown accessory mineral in meteorites. It crystallizes in the cubic crystal system, but typically occurs as anhedral grains between other minerals.

Oldhamite Market Value Calculator

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

Oldhamite Localities Map

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

Map preview

North ZoneCentral RidgeSouth Basin

Key Characteristics

Formation of Oldhamite

It was first described in 1862 for an occurrence in the Bustee meteorite, Gorakhpur, Uttar Pradesh, India. It was named for Irish geologist Thomas Oldham (1816–1878), the Director of the Indian Geological Survey. It occurs as an interstitial mineral phase between silicate minerals in enstatite chondrite and achondrite meteorites. It occurs in association with enstatite, augite, niningerite, osbornite, troilite, gypsum and calcite. It has been reported from a variety of meteorite locations around the world including the Allan Hills 84001 meteorite of Antarctica. It has also been reported from a slag occurrence in France and a coal deposit in Poland.