mineral

Chalcedony (Yellow/Amber variety)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Honey-yellow, translucent to opaque; Luster: Waxy to vitreous; Crystal Structure: Cryptocrystalline (trigonal/monoclinic); Cleavage: None; Fracture: Conchoidal.

Hardness: 6
Color: Honey-yellow, translucent to opaque
Luster: Waxy to vitreous

Identified July 5, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Honey-yellow, translucent to opaque; Luster: Waxy to vitreous; Crystal Structure: Cryptocrystalline (trigonal/monoclinic); Cleavage: None; Fracture: Conchoidal.

Formation & geological history

Formed through the deposition of silica from aqueous solutions, typically in volcanic cavities (vesicles) or sedimentary environments. It develops as a microcrystalline mass over thousands of years.

Uses & applications

Commonly used for lapidary work, jewelry (cabs or beads), tumbled stones for healing practices, and as a collector's specimen.

Geological facts

Chalcedony is a cryptocrystalline form of silica, meaning its crystals are too small to be seen under a normal microscope. The yellow color is often attributed to trace inclusions of iron hydroxides like goethite.

Field identification & locations

Identify in the field by its waxy luster, lack of visible crystals, and its ability to scratch glass. Found worldwide in riverbeds, deserts, and volcanic regions. Common locations include Brazil, India, and the USA (southwest).