sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Red, brown, and black; Luster: Vitreous to greasy; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red, brown, and black
Luster: Vitreous to greasy

Identified June 8, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Red, brown, and black; Luster: Vitreous to greasy; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.91

Formation & geological history

Formed from silica-rich fluids that percolate through volcanic or sedimentary rock, often in hydrothermal environments or via diagenesis where silica replaces other materials. Many varieties date back millions of years to the Paleozoic or Mesozoic eras.

Uses & applications

Used primarily as decorative gemstones, in jewelry (cabochons), as metaphysical healing crystals, and historically for making tools and seals.

Geological facts

Jasper is an opaque variety of chalcedony. The name stems from the Greek 'iaspis', meaning spotted stone. It has been used by ancient civilizations for protective amulets for thousands of years.

Field identification & locations

Identify by its opacity, high hardness (will scratch glass), and smooth conchoidal fracture. Commonly found in riverbeds, mountains, and deserts in Brazil, India, and the Western United States.