How do I identify Braggite?

Braggite can be identified by its hardness of 5 on the Mohs scale. Look for these key characteristics when examining specimens.

How hard is Braggite?

Braggite has a hardness of 5 on the Mohs scale. This gives it moderate hardness.

Braggite

A variety of Minerals

What is Braggite?

Braggite is a sulfide mineral of platinum, palladium and nickel with chemical formula: (Pt, Pd, Ni)S. It is a dense (specific gravity of 10), steel grey, opaque mineral which crystallizes in the tetragonal crystal system. It is the central member in the platinum group end-members cooperite and vysotskite. It was first described in 1932 for an occurrence in the Bushveld Igneous Complex of South Africa. Its name came from William Henry Bragg (1862–1942) and his son, William Lawrence Bragg (1890–1971). It was the first mineral that was discovered with the assistance of X rays. It occurs as magmatic segregations in layered igneous intrusions such as Bushveld, the Stillwater igneous complex, the Lac des Îles igneous complex, the island of Rùm intrusive, the Great Dyke and many others. It is one of the most common platinum group minerals.

Braggite Market Value Calculator

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

Braggite Localities Map

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

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Braggite

Braggite appears steel grey to silvery white to the naked eye. When viewed through a petrographic microscope, under plane polarized light, braggite is white and slightly bireflectant and lacks reflectance pleochroism. Observing between crossed polars, its anisotropy is distinct in air and is characterized by a purplish-grey to brown-grey tint. Relatively large crystals (up to 8 mm long) are not unusual for braggite and fracturing is common. Braggite has a measured specific gravity of 10 and calculated specific gravity of 9.383. Twinning is rarely observed. Braggite was found to have microindentation VHN values ranging from 973-1015.

Composition of Braggite

The braggite composition series is between the platinum rich cooperite and palladium rich vysotskite end members in solid solution and is thus considered of primary economic importance as an ore for both of these precious metals. Braggite, as well as vysotskite, was named prior to knowledge of phase relations in the Pt-Pd-S System and prior to the extensive microprobe analyses now available. Using electron probe analyses the average proportions for metal in the sulfide structure were determined to be 64 percent Pt, 27 percent Pd, and 14 percent Ni. When based on the unit cell content, this approximates to Pt5Pd2NiS8.