sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to tan; Luster: Waxy to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brownish-red to tan
Luster: Waxy to dull

Identified April 13, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to tan; Luster: Waxy to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.91

Formation & geological history

Formed through the infiltration of silica into volcanic ash or fine sediments (silicification). This specimen is a water-worn river pebble, shaped by fluvial erosion over thousands of years.

Uses & applications

Used in gemstone carving, jewelry making (cabochons), and as a collector's stone for its smooth texture and color.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'jasper' means 'spotted or speckled stone', derived from Old French jaspre.

Field identification & locations

Identify in the field by its opacity (it does not transmit light like quartz), smooth waxy feel when wet, and inability to be scratched by a steel knife. Commonly found in riverbeds and beaches.