Lustrous Sperrylite Crystal in Matrix
SULFIDES; ARSENIDES · ISOMETRIC

Sperrylite

PtAs2

Hardness
6–7
Streak
Dark gray to black
Spec. Gravity
10–11
System
Isometric

About

Sperrylite is a rare mineral composed primarily of the precious metal platinum. Aside from native Platinum, Sperrylite is the only platinum ore of any economic importance. It forms in highly lustrous crystals that can be very well-formed, making this mineral a novelty for collectors due to its value. Sperrylite is named after Francis Louis Sperry (1861-1906), a chemist who discovered this mineral at Sudbury, Ontario in 1889.

Crystal Forms & Aggregates

In cubes with modified octahedral faces, and less commonly octahedral with modified cubic faces. Crystals, which are never large, may be in grouped clusters or individually formed. Also in distorted crystal groups and irregular fractured crystal masses. Crystals often contain irregular surface cracks.

Striking Features

Environment

Uses

Sperrylite is an important ore of the precious metal platinum, and good crystals are highly valued by mineral collectors.

Noteworthy Localities

The original locality where Sperrylite was first identified is the Vermilion Mine, Denison Township, Sudbury District, Ontario. This famous locality still produces small lustrous crystals in the old mine dumps. Another well-known Sperrylite deposit in the Sudbury District is the Broken Hammer Deposit, Wisner Township, which produces crystals in very sharp form.
The largest and best-formed Sperrylite crystals come from the Talnakh deposit, near Noril'sk, Eastern-Siberian Region, Russia. Sperrylite is of economic value and mined for its platinum content at the Bushveld Complex, Limpopo Province, South Africa. In the U.S., waterworn crystals were found in alluvial placer deposits at Mason Mountain, Macon County, North Carolina.

Common Mineral Associations

Distinguishing Similar Minerals

Crystal forms

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Cubic with Octahedral Modifications
Octahedral with Cubic Faces