sedimentary

Tumbled jasper or iron-rich chert

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque tan, ochre, brown, and rusty-red coloration with a dull to waxy luster. Dense, fine-grained, and lacking visible cleavage; the apparent cavity may contain weathered quartz or iron-oxide material.

Identified September 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed as silica-rich sediment or chert that later absorbed iron-bearing fluids and oxidized. Such material can range from Paleozoic to younger geological ages; the exact age cannot be determined from the photograph.

Uses & applications

Used as ornamental stone, lapidary material, beads, cabochons, and inexpensive carvings; occasionally used as aggregate or decorative rock.

Geological facts

Jasper is an opaque variety of chalcedony, and its colors commonly result from hematite, limonite, or goethite. A polished surface and strong translucency at thin edges would help distinguish it from ordinary iron-stained sandstone.

Field identification & locations

Commonly found in volcanic, hydrothermal, and sedimentary environments worldwide, especially where silica-rich fluids altered iron-bearing rocks. A fresh unpolished surface, conchoidal fracture, and ability to scratch glass support a chert/jasper identification.