sedimentary

Red Jasper

Jasper (Silicon Dioxide Si₂O₃)

Hardness: 6.5-7 (Mohs), Color: Brick red to brownish-red, Luster: Vitreous to dull, Crystal Structure: Microcrystalline trigonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.58–2.91

Hardness: 6

Identified May 29, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs), Color: Brick red to brownish-red, Luster: Vitreous to dull, Crystal Structure: Microcrystalline trigonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.58–2.91

Formation & geological history

Formed from the deposition of silica in groundwater within sedimentary or metamorphic environments, often associated with volcanic ash or hydrothermal vents. It gains its red color from high iron inclusions.

Uses & applications

Used primarily in lapidary work for cabochons, beads, and ornamental carvings. Historically used for seals, jewelry, and as a source of red pigment.

Geological facts

Red Jasper was a favorite in the ancient world, often called the 'stone of endurance.' It is a member of the chalcedony family and its opacity is what distinguishes it from agate.

Field identification & locations

Identify by its hardness (will scratch glass), opaque nature, and smooth waxy feel when polished. Commonly found in river beds and gravel deposits globally, including India, Brazil, and the USA.