sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Dark brown to reddish-brown with orange inclusions; Luster: Dull to waxy; Crystal structure: Microcrystalline (trigonal); Cleavage: None; Specific gravity: 2.58-2.91

Hardness: 6
Color: Dark brown to reddish-brown with orange inclusions
Luster: Dull to waxy

Identified June 18, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Dark brown to reddish-brown with orange inclusions; Luster: Dull to waxy; Crystal structure: Microcrystalline (trigonal); Cleavage: None; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the accumulation of fine-grained silica, typically in volcanic ash or sedimentary environments where minerals fill cracks as part of the lithification process. Often found in riverbeds due to high resistance to erosion.

Uses & applications

Used primarily for ornamental purposes, jewelry (cabochons), lapidary art, and as a collector's specimen. Historically used for making tools and seals.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Old French 'jaspre', meaning 'spotted or speckled stone'. Some specimens contain iron oxide which gives them their characteristic red and brown hues.

Field identification & locations

Identify by its waxy luster when wet, high hardness (will scratch glass), and its lack of transparency even when sliced thin. This specific specimen appears water-worn, likely found in a river or creek bed.