Rock Identifier
Tumbled red jasper (probable) (Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides) — mineral
mineral

Tumbled red jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Small rounded, polished pebble with reddish-brown color, opaque to slightly translucent edges, and dull-to-waxy luster. Hardness is about 6.5–7 Mohs; lacks visible cleavage and has a cryptocrystalline quartz structure; specific gravity is approximately 2.6.

Identified More mineral
Explore Tumbled red jasper (probable) in the encyclopedia →

Identify your own rocks.

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

Physical properties

Small rounded, polished pebble with reddish-brown color, opaque to slightly translucent edges, and dull-to-waxy luster. Hardness is about 6.5–7 Mohs; lacks visible cleavage and has a cryptocrystalline quartz structure; specific gravity is approximately 2.6.

Formation & geological history

Forms when silica-rich fluids replace or fill cavities in volcanic and sedimentary rocks, with iron producing the red coloration. Its precise geological age cannot be determined from the photograph; tumbled examples are mechanically polished from natural material.

Uses & applications

Used for cabochons, beads, carvings, lapidary pieces, and inexpensive collectible specimens; it has little structural or industrial value.

Geological facts

Jasper is a variety of opaque chalcedony, though many commercial pieces are sold broadly as “red jasper.” Similar-looking red glass, dyed quartz, or carnelian can be distinguished by testing hardness and examining internal texture.

Field identification & locations

Common sources include India, Madagascar, Brazil, the United States, and Australia. Field identification relies on opaque iron-red coloration, fine grain, quartz-like hardness, and absence of bubbles or conchoidal glass texture.