Rock Identifier
Tumbled jasper pebble (likely ocean jasper or brecciated jasper) (Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions) — mineral
mineral

Tumbled jasper pebble (likely ocean jasper or brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque, mottled yellow-green, brown, gray, and reddish coloration; dull to waxy luster; cryptocrystalline quartz with no visible cleavage. The rounded shape indicates natural water wear or tumbling.

Identified More mineral
Explore Tumbled jasper pebble (likely ocean jasper or brecciated jasper) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness about 6.5–7 Mohs; opaque, mottled yellow-green, brown, gray, and reddish coloration; dull to waxy luster; cryptocrystalline quartz with no visible cleavage. The rounded shape indicates natural water wear or tumbling.

Formation & geological history

Jasper forms when silica-rich fluids replace or cement volcanic ash, sediment, or rock fractures, with iron oxides producing the earthy colors. Formation ages vary widely, commonly from Paleozoic to Cenozoic deposits.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, and decorative objects; durable but generally not a high-value gemstone.

Geological facts

Jasper is a variety of opaque chalcedony and may contain hematite, goethite, clay, or volcanic fragments. Individual patterns are often diagnostic of a particular locality.

Field identification & locations

Identify by its opaque, fine-grained texture, hardness, waxy surface, and resistance to scratching by steel; quartz-rich material should scratch glass. Common sources include Madagascar, Oregon, India, Brazil, and Mexico.