How do I identify Sellaite?

Sellaite can be identified by its hardness of 5 - 5.5 on the Mohs scale, Colourless color. Look for these key characteristics when examining specimens.

What color is Sellaite?

Sellaite typically appears in Colourless, white, colourless in transmitted light. Color can vary depending on impurities and formation conditions.

How hard is Sellaite?

Sellaite has a hardness of 5 - 5.5 on the Mohs scale. This gives it moderate hardness.

Sellaite

A variety of Minerals

What is Sellaite?

Sellaite is a magnesium fluoride mineral with the formula MgF2. It crystallizes in the tetragonal crystal system, typically as clear to white vitreous prisms. It may be fibrous and occur as radiating aggregates. It has a Mohs hardness of 5 to 6 and a specific gravity of 2.97 to 3.15. Refractive index values are nω = 1.378 and nε = 1.390.

Optical Properties

Refractive Index: 1.378-1.390
Birefringence: 0.010-0.012
Optical Character: Uniaxial negative

Sellaite Market Value Calculator

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

Sellaite Localities Map

See where Sellaite 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 Sellaite

Sellaite was first described in 1868 and named for Italian mining engineer and mineralogist Quintino Sella (1827–1884). Its type locality is the glacier de Gébroulaz [fr] in France, where it occurred inside bitumen-bearing dolomite-anhydrite clasts within a moraine deposit. It has been reported in an evaporite deposit at Bleicherode; within volcanic ejecta and fumaroles at Vesuvius; in a metamorphic magnesite deposit at Serra das Éguas [pt]; and in sodic alkali granite near Gjerdingen [no].