Home > Braggite

Braggite

A species of Minerals

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.

Hardness:

Density:

9.383 g/cm³

General Info About Braggite

Instantly Identify Rocks with a Snap

Snap a photo for instant rock/gemstone/mineral ID and properties analysis, gaining quick insights on characteristics, market value, collecting tips, care, real vs fake, and health risks, etc.

Download the App for Free

Physical Properties of Braggite

Hardness

5 , Soft

Density

9.383 g/cm³, Obviously Heavy Weight

AI rock expert in your pocket

Chemical Properties of Braggite

Formula

(Pt,Pd,Ni)S

Elements listed

Ni, Pd, Pt, S

Characteristics of Braggite

Your Comprehensive Rock Characteristics Guide

In-depth exploration of rock types, features, and formation aspects

Download the App for Free

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.

Common Questions People Also Ask

Get Quick Rock Answers with a Snap

Snap a photo for instant rock ID and answers on characteristics, market value, collecting tips, care, real vs fake, and health risks, etc.

Download the App for Free