metamorphic
Red jasper
Jasper, microcrystalline quartz (SiO₂) colored mainly by iron oxides
AI-generated identification · may be incorrectOpaque dark red-brown, fine-grained, earthy to dull luster with faint lighter streaks; quartz hardness about 6.5–7 Mohs, no visible cleavage, conchoidal to uneven fracture, specific gravity about 2.5–2.7. The specimen appears naturally rough and unpolished.
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Physical properties
Opaque dark red-brown, fine-grained, earthy to dull luster with faint lighter streaks; quartz hardness about 6.5–7 Mohs, no visible cleavage, conchoidal to uneven fracture, specific gravity about 2.5–2.7. The specimen appears naturally rough and unpolished.
Formation & geological history
Jasper forms when silica-rich fluids cement or replace sediments and volcanic material, with iron oxides producing the red color; deposits range from Precambrian to younger ages. Exact age and locality cannot be determined from the image.
Uses & applications
Used for cabochons, beads, carvings, bookends, lapidary pieces, and ornamental stone; occasionally used as crushed decorative aggregate. Common specimens generally have modest market value.
Geological facts
Jasper is a variety of opaque chalcedony or microcrystalline quartz rather than a distinct mineral species. Red coloration typically comes from hematite or related iron-oxide inclusions.
Field identification & locations
Identify it by its opaque brick-red color, very fine texture, toughness, and inability to scratch with a steel knife; quartz or glass can scratch it. Common worldwide, including India, Madagascar, Brazil, Australia, and the western United States.
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