Mineral

Yellow Quartz (Chalcedony/Agate)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent yellow to honey-brown; Luster: Waxy to vitreous; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (Conchoidal fracture); Specific gravity: 2.60–2.65.

Hardness: 7 on Mohs scale
Color: Translucent yellow to honey-brown
Luster: Waxy to vitreous

Identified March 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich groundwater depositing in cavities of volcanic or sedimentary rocks. The yellow hue is often caused by trace inclusions of iron oxides (limonite or goethite). These can be found in deposits ranging from recent quaternary to millions of years old.

Uses & applications

Commonly used in lapidary arts for tumbling, cabochons, and jewelry beads. Also used as decorative landscaping stones and collected as healing crystals in metaphysical communities.

Geological facts

This specimen appears to be a water-worn river pebble. When quartz is cryptocrystalline (microscopic crystals) and translucent, it is specifically called chalcedony. If it shows banding when sliced, it is classified as agate.

Field identification & locations

Identify in the field by its translucency and its ability to scratch glass (hardness test). Look for a smooth, 'waxy' texture on water-worn surfaces. Commonly found in riverbeds, gravel pits, and desert washes worldwide.

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