Rock Identifier
Likely tumbled jasper or chert pebble (Microcrystalline quartz (SiO₂), possibly iron-stained jasper/chert) — mineral
mineral

Likely tumbled jasper or chert pebble

Microcrystalline quartz (SiO₂), possibly iron-stained jasper/chert

AI-generated identification · may be incorrect

Small rounded, opaque gray-green and reddish-brown specimen with a dull to faintly waxy luster; likely hardness 6.5–7 Mohs, no visible cleavage, and cryptocrystalline structure. The blurred image prevents confident identification or reliable specific-gravity assessment.

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Physical properties

Small rounded, opaque gray-green and reddish-brown specimen with a dull to faintly waxy luster; likely hardness 6.5–7 Mohs, no visible cleavage, and cryptocrystalline structure. The blurred image prevents confident identification or reliable specific-gravity assessment.

Formation & geological history

Formed when silica-rich fluids or sediment lithified and recrystallized into microcrystalline quartz, with iron oxides producing red-brown coloration; age may range from Paleozoic to younger depending on locality. Its rounded shape indicates natural water wear or tumbling.

Uses & applications

Used as a low-cost lapidary stone for cabochons, beads, carvings, and polished specimens; generally not used structurally. Common tumbled pieces are mainly decorative or educational.

Geological facts

Jasper and chert are varieties of chalcedony/microcrystalline quartz and can look very similar. A steel file should not scratch it easily, while it may scratch ordinary glass.

Field identification & locations

Common in river gravels and silica-rich volcanic or sedimentary terrains worldwide, including the United States, Mexico, Australia, and India. A sharper photograph, locality, streak, translucency, and scratch testing would improve identification.