Rock Identifier
Tumbled yellow jasper (likely iron-stained chalcedony) (Jasper, microcrystalline quartz (SiO₂) with iron-oxide inclusions) — mineral
mineral

Tumbled yellow jasper (likely iron-stained chalcedony)

Jasper, microcrystalline quartz (SiO₂) with iron-oxide inclusions

AI-generated identification · may be incorrect

Opaque mustard-yellow to ochre, earthy/waxy luster, fine-grained and noncrystalline to the naked eye; Mohs hardness about 6.5–7, no cleavage, specific gravity roughly 2.6. The rounded shape indicates tumbling or natural abrasion.

Identified More mineral
Explore Tumbled yellow jasper (likely iron-stained chalcedony) in the encyclopedia →

Identify your own rocks.

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

Physical properties

Opaque mustard-yellow to ochre, earthy/waxy luster, fine-grained and noncrystalline to the naked eye; Mohs hardness about 6.5–7, no cleavage, specific gravity roughly 2.6. The rounded shape indicates tumbling or natural abrasion.

Formation & geological history

Forms when silica-rich groundwater replaces or fills cavities in volcanic or sedimentary rocks, with iron oxides producing the yellow color; deposits range from Precambrian to recent ages. Exact locality cannot be determined from the image.

Uses & applications

Used for cabochons, beads, carvings, ornamental objects, and inexpensive polished specimens; it has little industrial value compared with ordinary quartz.

Geological facts

Jasper is a variety of opaque chalcedony, often grouped commercially by color or locality rather than as a distinct mineral species. Yellow coloration commonly reflects limonite or goethite.

Field identification & locations

Identify by its opaque color, fine texture, glass-scratching hardness, and lack of visible grains or cleavage; common sources include Brazil, India, Madagascar, the western United States, and Australia.