mineral

Sphalerite

Zinc Sulfide (Zn,Fe)S

Hardness: 3.5 to 4.0; Color: yellowish-brown to black; Luster: Adamantine to resinous; Crystal structure: Isometric (regularly forms as tetrahedrons); Cleavage: Perfect dodecahedral in six directions; Specific gravity: 3.9 to 4.1.

Hardness: 3
Color: yellowish-brown to black
Luster: Adamantine to resinous

Identified December 29, 2025More mineral →

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Physical properties

Formation & geological history

Forms primarily in hydrothermal veins and replacement deposits. It is often found in sedimentary environments through precipitation in limestone and dolomite. It is a common sulfide mineral across various geological ages.

Uses & applications

The primary ore of zinc, used for galvanizing iron, making brass and bronze, and in the production of batteries. High-quality specimens are cut as gemstones, though they are soft for jewelry. Highly valued by mineral collectors.

Geological facts

Sphalerite is often called 'Black-Jack' by miners due to its dark color. It is known for its high dispersion (0.156), which is over three times that of a diamond, resulting in spectacular 'fire' in clear specimens.

Field identification & locations

Identify in the field by its resinous luster, perfect cleavage, and a pale yellow to brown streak. Commonly found in locations like Joplin (Missouri), Leadville (Colorado), and various mines in Spain and Mexico.