gemstone

Tumbled carnelian (probable)

Chalcedony, microcrystalline quartz (SiO₂), iron-oxide colored

AI-generated identification · may be incorrect

Orange-brown, translucent at thin edges, with a waxy to vitreous luster and faint cloudy banding. Mohs hardness 6.5–7; no cleavage; cryptocrystalline trigonal quartz; typical specific gravity about 2.58–2.64.

Identified September 14, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, later acquiring its orange-red color from dispersed iron oxides. Commonly Cenozoic to older volcanic-hosted material; exact age cannot be determined from the image.

Uses & applications

Used for cabochons, beads, carvings, and inexpensive ornamental objects; also collected as a polished/tumbled stone. Value is generally modest unless color, translucency, and pattern are exceptional.

Geological facts

Carnelian is an orange variety of chalcedony; deeper red material is often called sard. Heating or dyeing can intensify its color, so untreated status may require testing.

Field identification & locations

Likely carnelian if it is naturally orange throughout; identify by hardness, waxy luster, translucency, and lack of cleavage. Common sources include India, Brazil, Uruguay, Madagascar, and Germany; this specimen appears tumbled and polished.