sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs); Color: Mustard yellow or tan; Luster: Dull or waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Opaque.

Hardness: 6
Color: Mustard yellow or tan
Luster: Dull or waxy

Identified July 21, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Mustard yellow or tan; Luster: Dull or waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Opaque.

Formation & geological history

Formed from the deposition of silica-rich waters within sedimentary environments or volcanic ash beds. The color is derived from iron oxides (Goethite) trapped within the quartz structure.

Uses & applications

Used primarily in lapidary work for cabochons, beads, and decorative carvings. Also used in aquarium gravel and as a collector's stone.

Geological facts

Jasper is an opaque variety of chalcedony. Historically, yellow jasper was used as a 'stone of protection' for spiritual and physical travel. Its name comes from the Greek 'iaspis', meaning 'spotted stone'.

Field identification & locations

Identify by its hardness (will scratch glass) and smooth, waxy feel when wet or polished. Commonly found in riverbeds, deserts, and coastal areas globally, notably in India, Russia, and the USA.