How do I identify Stillwaterite?

Stillwaterite can be identified by its hardness of 4.5 on the Mohs scale. Look for these key characteristics when examining specimens.

How hard is Stillwaterite?

Stillwaterite has a hardness of 4.5 on the Mohs scale. This gives it moderate hardness.

Stillwaterite

A variety of Minerals

What is Stillwaterite?

The palladium arsenide mineral Stillwaterite has a general formula of Pd8As3. Stillwaterite was first discovered in the Banded and Upper zones of the Stillwater igneous complex in Montana, United States, and has been reported in the Lac-des-Iles area of Ontario, Canada. Outside of North America, this rare mineral has been found in northern Finland.

Stillwaterite Market Value Calculator

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

Stillwaterite Localities Map

See where Stillwaterite 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

Characteristics of Stillwaterite

Because it is opaque, stillwaterite is most commonly viewed under reflected light, appearing light creamy gray in color. It is weakly anisotropic in air, displaying dark gray to brownish gray color. In oil immersion, it shows distinct anisotropy with brownish black color and a blue to yellow-brown tinge. Hexagonal minerals such as stillwaterite are referred to as uniaxial crystals because they have only one direction, along the optic axis, in which light is not reoriented.