mineral

Yellow Agate (Chalcedony)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Honey-yellow, translucent white, and brownish-orange; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Honey-yellow, translucent white, and brownish-orange
Luster: Waxy to vitreous

Identified July 2, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks, particularly volcanic lavas. These bands develop in layers over time as mineral-rich fluids seep into the voids.

Uses & applications

Commonly used for ornamental carvings, tumble polishing, cabochon jewelry, and as a collector's specimen. Its hardness also makes it useful for industrial mortars and pestles.

Geological facts

Agate is named after the Achates River in Sicily where it was first discovered in ancient times. Yellow agate is often associated with sunlight and energy in metaphysical circles.

Field identification & locations

Identify in the field by its waxy luster, conchoidal fracture (rounded, glass-like breaks), and characteristic banding. Often found in riverbeds or volcanic regions like Brazil, India, and the United States (western states).