sedimentary

Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Typically red, brown, yellow, or green; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91

Hardness: 6
Color: Typically red, brown, yellow, or green
Luster: Vitreous to dull

Identified January 23, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Typically red, brown, yellow, or green; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from water or volcanic ash. It often originates in hydrothermal veins or as a chemical sedimentary rock in marine environments. Most specimens date back to the Precambrian or Paleozoic eras.

Uses & applications

Used widely in the manufacturing of semi-precious jewelry (beads, cabochons), ornamental objects like vases or seals, and remains a highly sought-after material for lapidary hobbyists and geological collectors.

Geological facts

Jasper is an opaque variety of chalcedony. Its red color is usually attributed to iron(III) inclusions. In ancient times, it was believed to provide physical protection and was known as the 'supreme nurturer' in various cultures.

Field identification & locations

Identify in the field by its opacity (unlike translucent agate), conchoidal fracture (smooth, curved breaks), and hardness (it will easily scratch glass). It is commonly found in desert regions of the Western USA, Brazil, India, and Australia.