sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Red/Brick-red; Luster: Vitreous to waxy; Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red/Brick-red
Luster: Vitreous to waxy

Identified May 9, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Red/Brick-red; Luster: Vitreous to waxy; Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed through the accumulation of fine-grained silica (quartz/chalcedony) in sedimentary environments, often associated with hydrothermal activity or volcanic ash silica. The red color comes from high iron/hematite content.

Uses & applications

Widely used for lapidary work, jewelry (cabochons), polishing in rock tumblers, decorative ornaments, and metaphysical collecting.

Geological facts

The name comes from the Greek word 'iaspis', meaning spotted stone. It was a favorite gemstone in the ancient world, referenced in many historical texts and used in the seals of ancient civilizations.

Field identification & locations

Identify in the field by its opaque nature (it does not transmit light even when held to a bulb), its deep red color, and its ability to scratch glass. Commonly found in riverbeds and coastal regions globally, notably in the USA, India, and Brazil.