mineral

Yellow Chalcedony (likely carnelian or yellow agate)

Silicon Dioxide (SiO₂)

Hardness: 6.5-7 on Mohs scale; Color: Translucent yellow to honey-orange; Luster: Waxy to vitreous; Crystal Structure: Cryptocrystalline (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.64

Hardness: 6
Color: Translucent yellow to honey-orange
Luster: Waxy to vitreous

Identified March 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in cavities of igneous rocks or sedimentary formations. Its color is often derived from trace amounts of iron oxide impurities incorporated during mineralization.

Uses & applications

Predominantly used for lapidary work, jewelry (beads, cabochons), ornamental carvings, and as a collector's specimen for healing stone enthusiasts.

Geological facts

Chalcedony was highly valued in antiquity; the Minoans used it for cylinder seals. Its cryptocrystalline nature means the quartz crystals are so small they can only be seen under extreme magnification.

Field identification & locations

Identify in the field by its waxy texture, smooth rounded edges (when water-worn), and lack of visible cleavage planes. Common in riverbeds, volcanic deposits, and desert regions globally (notably Brazil, India, and the Western USA).

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