sedimentary

Banded Jasper / Chert

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Red, brown, yellow, tan; Luster: Dull to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Hardness: 6
Color: Red, brown, yellow, tan
Luster: Dull to waxy

Identified June 7, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Red, brown, yellow, tan; Luster: Dull to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Formation & geological history

Formed through the accumulation of silica-rich microfossils or chemical precipitation in ancient marine or hydrothermal environments. Iron oxides produce the red and brown coloration. These deposits can range from Precambrian to Cenozoic in age.

Uses & applications

Used for lapidary work, cabochons for jewelry, garden landscaping, and as decorative display specimens for collectors.

Geological facts

The concentric and wavy bands are often referred to as 'picture jasper' if they resemble landscapes. Jasper has been used by humans for thousands of years to create both tools (knives/scrapers) and ornaments.

Field identification & locations

Identify in the field by its hardness (will scratch glass), conchoidal (shell-like) fracture, and opaque appearance. Found in desert regions, riverbeds, and volcanic ash deposits.