mineral

Yellow jasper / silicified breccia

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide staining and possible breccia fragments

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, opaque yellow, ochre, brown, and gray, with a waxy to dull luster and conchoidal fracture; no obvious cleavage. The irregular angular textures suggest silicified or brecciated material rather than a single crystal.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed when silica-rich fluids filled and replaced fractures or porous rock, while iron oxides produced the yellow-brown coloration. Such jasper commonly forms in volcanic or hydrothermal environments, generally at shallow crustal depths; a precise age cannot be determined from the image.

Uses & applications

Used as lapidary rough, cabochons, beads, carvings, and decorative stone; rarely used as aggregate or architectural material. Commercial value is usually modest unless the pattern and polish are exceptional.

Geological facts

Jasper is an opaque variety of chalcedony, unlike translucent agate. The dark patches may represent host-rock fragments, manganese/iron oxides, or weathered inclusions.

Field identification & locations

Identify by its opaque coloration, high hardness, waxy surface, and conchoidal edges; it should resist scratching from a steel knife. Commonly found in volcanic terrains and silica-rich replacement zones worldwide, including the western United States, Mexico, Brazil, and Australia.