sedimentary

Banded jasper

Jasper; microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities

AI-generated identification · may be incorrect

Typically opaque, fine-grained, and non-cleavable, with reddish-brown, tan, gray, or yellow bands and earthy to dull/waxy luster. Mohs hardness is about 6.5–7; quartz crystals are microscopic, so individual crystals are not usually visible.

Identified August 30, 2026More sedimentary →

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Physical properties

Formation & geological history

Usually forms when silica-rich fluids cement fine sediments or replace volcanic/chemical deposits, while iron oxides create the coloration and banding. Its exact geologic age cannot be determined from the photograph; jasper occurs from Precambrian to recent settings.

Uses & applications

Used for cabochons, carvings, ornaments, lapidary slabs, and tumbled stones; massive pieces are occasionally used as decorative stone. Common specimens generally have modest value.

Geological facts

The irregular pale veins may be quartz or chalcedony, and the darker reddish tones commonly reflect hematite or goethite. A broken surface should be relatively smooth and conchoidal rather than granular.

Field identification & locations

Look for opaque silica-rich material that scratches glass, resists a steel knife, and shows earthy red-brown banding; a streak test is usually white to pale. Common sources include volcanic terrains and iron-rich sedimentary formations worldwide.