sedimentary

Jasper (Multi-color Chert)

Silicon dioxide (SiO2)

Hardness: 6.5–7 on Mohs scale; Color: Dark green and yellow-ochre with red streaks; Luster: Dull to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58–2.91

Hardness: 6
Color: Dark green and yellow-ochre with red streaks
Luster: Dull to waxy

Identified April 9, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of silica-rich fluids in volcanic ash or sedimentary deposits. The colors are derived from mineral impurities (iron oxides for yellow/red, silicate minerals for green) during the lithification process, often dating back to the Paleozoic or Mesozoic eras.

Uses & applications

Used primarily as an ornamental stone, in lapidary work for cabochons, beads, and carvings, and as a decorative landscaping rock.

Geological facts

This specific piece is often referred to as 'Fancy Jasper' or 'Polychrome Jasper' due to its distinct color banding. Jasper is an opaque variety of chalcedony that has been used by humans for tools and jewelry since the Neolithic period.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel knife), smooth waxy feel when wet, and characteristic shell-like (conchoidal) fractures. Frequently found in riverbeds or desert regions where volcanic activity once occurred.

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