mineral

Orange chalcedony (possibly carnelian)

Microcrystalline quartz, SiO₂; iron-bearing chalcedony

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, waxy to dull luster, translucent orange-brown color, and no visible cleavage; composed of fibrous cryptocrystalline quartz. The specimen appears rough and naturally weathered, with iron-oxide staining and possible quartz veining.

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, with iron producing orange to red coloration. Chalcedony deposits range from Paleozoic to recent in age and occur worldwide.

Uses & applications

Used for beads, carvings, cabochons, lapidary work, and ornamental objects; attractive translucent material has modest gemstone value.

Geological facts

Carnelian is the red-orange, more translucent variety of chalcedony; color may intensify after heating or prolonged sunlight exposure. A precise identification requires testing translucency, hardness, and specific gravity.

Field identification & locations

Common sources include Brazil, Uruguay, India, Madagascar, Namibia, and the western United States. It can be distinguished from orange calcite by its greater hardness and lack of cleavage; a steel blade should not readily scratch it.