sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Brown, tan, reddish; Luster: Dull to waxy; Crystal Structure: Microcrystalline (trigonal); Cleavage: None, conchoidal fracture; Specific gravity: 2.58-2.91

Hardness: 6
Color: Brown, tan, reddish
Luster: Dull to waxy

Identified April 21, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Brown, tan, reddish; Luster: Dull to waxy; Crystal Structure: Microcrystalline (trigonal); Cleavage: None, conchoidal fracture; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the infiltration of silica-rich fluids into volcanic ash or fine sediment. The brown coloring is due to iron oxide impurities. This specific specimen has been polished by fluvial (river) or glacial action into a 'cobble' or 'river stone'.

Uses & applications

Commonly used in lapidary arts, jewelry (cabochons), landscape decoration, and as worry stones for collectors.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It is known as the 'Supreme Nurturer' in metaphysical circles.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its smooth, rounded, waxy surface when found in riverbeds. Look for bands or irregular inclusions of different colors.