mineral
Tumbled yellow-orange chalcedony (likely carnelian)
Microcrystalline quartz, SiO₂; iron-bearing variety commonly called carnelian
AI-generated identification · may be incorrectHardness 6.5–7 Mohs; translucent honey-yellow to orange, with waxy to vitreous luster and no visible cleavage. It is cryptocrystalline quartz, typically with a smooth tumbled surface and conchoidal fracture.
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Physical properties
Hardness 6.5–7 Mohs; translucent honey-yellow to orange, with waxy to vitreous luster and no visible cleavage. It is cryptocrystalline quartz, typically with a smooth tumbled surface and conchoidal fracture.
Formation & geological history
Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, later colored by dispersed iron oxides; deposits range from ancient to modern, commonly associated with Cenozoic volcanic terrains.
Uses & applications
Used for inexpensive cabochons, beads, carvings, lapidary pieces, and ornamental objects; durable enough for jewelry and small decorative items.
Geological facts
Carnelian is the orange-red member of the chalcedony family; yellow material may also be sold as yellow chalcedony or citrine-like chalcedony. Color can be enhanced by heating or dyeing.
Field identification & locations
Identify by its even color, translucency, waxy appearance, lack of cleavage, and quartz-level hardness; it should scratch ordinary glass but not be scratched by a steel knife. Common sources include India, Brazil, Uruguay, Madagascar, and the United States.
