gemstone

Tumbled carnelian

Chalcedony, a microcrystalline variety of quartz (SiO₂)

AI-generated identification · may be incorrect

The small, rounded specimen is translucent honey-brown with a waxy to vitreous luster. Quartz hardness is 7 on the Mohs scale; its crystals are microscopic and it has no cleavage. The image alone cannot confirm that it is carnelian rather than another brown chalcedony.

Identified October 12, 2026More gemstone →

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Physical properties

Formation & geological history

Chalcedony forms when silica-rich fluids deposit in cavities and fractures, commonly in volcanic rocks. Carnelian’s iron coloring develops through trace iron compounds; its geological age depends on the deposit.

Uses & applications

Used for beads, cabochons, carvings, and inexpensive jewelry; tumbling smooths its surface.

Geological facts

Carnelian is a traditional variety of agate/chalcedony valued since antiquity for seals and ornaments.

Field identification & locations

Look for translucent orange-to-brown color, waxy luster, and hardness sufficient to scratch glass; common sources include India, Brazil, and Uruguay. The pictured piece is too small to identify its locality or verify its variety.