mineral

Cinnabar

Mercury(II) sulfide (HgS)

Hardness: 2.0-2.5 on Mohs scale; Color: bright scarlet to brownish red; Luster: Adamantine to dull; Crystal structure: Trigonal; Cleavage: Perfect rhombohedral; Specific gravity: 8.1

Hardness: 2
Color: bright scarlet to brownish red
Luster: Adamantine to dull

Identified May 3, 2026More mineral →

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Physical properties

Hardness: 2.0-2.5 on Mohs scale; Color: bright scarlet to brownish red; Luster: Adamantine to dull; Crystal structure: Trigonal; Cleavage: Perfect rhombohedral; Specific gravity: 8.1

Formation & geological history

Formed in hydrothermal veins near recent volcanic activity or hot springs, usually at low temperatures. Common in sedimentary rocks like limestone and shale.

Uses & applications

Historically used as a red pigment (vermilion) and the primary ore for mercury extraction. Today, it is primarily a collector's mineral.

Geological facts

Cinnabar is toxic due to its mercury content. The name comes from the Greek 'kinnabari', likely of Persian origin. Ancient Romans used it extensively for wall paintings in Pompeii.

Field identification & locations

Identify by its heavy weight (high density) and bright red streak. Caution should be taken when handling. Found in Almadn (Spain), Huancavelica (Peru), and Guizhou (China).