mineral
Red jasper
Jasper, an opaque microcrystalline quartz variety (SiO₂), colored mainly by iron oxides
AI-generated identification · may be incorrectTypically reddish-brown with gray or yellow matrix, opaque, earthy to waxy luster, hardness about 6.5–7 Mohs, no cleavage, and conchoidal-to-irregular fracture. The rounded shape indicates tumbling or natural abrasion; the specimen may also be brecciated jasper.
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Physical properties
Typically reddish-brown with gray or yellow matrix, opaque, earthy to waxy luster, hardness about 6.5–7 Mohs, no cleavage, and conchoidal-to-irregular fracture. The rounded shape indicates tumbling or natural abrasion; the specimen may also be brecciated jasper.
Formation & geological history
Forms when silica-rich groundwater replaces or cements sediments and volcanic material, with iron oxides producing the red color. Deposits occur in many ages, commonly in Precambrian to younger volcanic and sedimentary terrains.
Uses & applications
Used for cabochons, beads, carvings, tumbled stones, ornaments, and lapidary work; larger jasper is occasionally used decoratively. Common pieces have modest collector value.
Geological facts
Jasper is technically a rock rather than a single mineral, despite its quartz-dominated composition. Color patterns and matrix are controlled by iron, manganese, clay, and included rock fragments.
Field identification & locations
Identify it by its opaque red coloration, fine-grained texture, substantial weight, and inability to scratch with a steel knife while scratching glass. Common sources include India, Madagascar, Brazil, the United States, and Australia; this could also be red brecciated jasper.
