Brecciated jasper, possibly rainforest jasper or brecciated rhyolite

Opaque, irregularly mottled and brecciated stone with dark green-gray matrix and angular pink, red, brown, and pale fragments. Likely hardness about 6.5–7 on the Mohs scale; generally dull to waxy luster on a rough surface and capable of taking a good polish. Jasper is cryptocrystalline quartz with no visible individual crystals and no prominent cleavage. Typical specific gravity is approximately 2.55–2.70. The image does not show enough detail to distinguish confidently between jasper and a fine-grained altered volcanic rock.

Jasper forms when silica-rich fluids replace or cement fine sediment, volcanic ash, or rock fragments. Brecciated varieties form when earlier rock is fractured and the fragments are later cemented by silica-rich material, often with iron and green silicate minerals. If this is rainforest jasper, it is generally considered a variety of altered rhyolite rather than true sedimentary jasper. The exact geological age cannot be determined from the photograph; deposits range from Precambrian to much younger volcanic and hydrothermal settings.

Usually collected as an ornamental stone and cut into cabochons, beads, slabs, carvings, polished stones, and bookends. It may be used decoratively in small-scale lapidary work but is not normally an important industrial or construction stone. Value is primarily aesthetic and depends on pattern, color contrast, polishability, and provenance.

The angular fragments and contrasting colors indicate a breccia-like texture. Red coloration commonly reflects oxidized iron minerals, while green coloration can result from epidote, chlorite, actinolite, or other alteration minerals. Similar-looking material is sold under several trade names, including brecciated jasper, rainforest jasper, green jasper, and occasionally dragon-blood jasper; these names are not always used consistently in the mineral trade.

In the field, look for a dense, opaque rock with a smooth or waxy fracture, no obvious glassy volcanic surface, and strong resistance to scratching. A steel knife should generally fail to scratch fresh material, while quartz or a hardened steel file may scratch it. A streak test on unglazed porcelain is often white to pale gray, although iron-rich material can leave a reddish streak. Acid testing is usually negative. A freshly cut and polished face, hardness test, specific-gravity measurement, and thin-section or laboratory analysis would be needed for a confident distinction from altered rhyolite, epidote-bearing volcanic rock, or unakite. Common jasper occurrences include India, Madagascar, Australia, Brazil, South Africa, Mexico, and the western United States.