mineral

Yellow Chalcedony

Cryptocrystalline Quartz (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: honey-yellow, amber, or golden; Luster: waxy to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: none; Specific gravity: 2.60-2.64

Hardness: 6
Color: honey-yellow, amber, or golden
Luster: waxy to vitreous

Identified June 9, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: honey-yellow, amber, or golden; Luster: waxy to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: none; Specific gravity: 2.60-2.64

Formation & geological history

Formed by the deposition of silica from groundwater in cavities of volcanic and sedimentary rocks. Its formation can occur over millions of years as silica-rich fluids percolate through rock voids.

Uses & applications

Primarily used as a gemstone for jewelry, cabochons, and decorative carvings. It is also highly popular in the metaphysical community and for rock tumbling/collecting.

Geological facts

The name 'Chalcedony' is derived from the ancient Greek town of Chalkedon. This yellow variety is often associated with solar energy in folklore and is a close relative of agate and carnelian.

Field identification & locations

Identify by its characteristic waxy luster, translucency, and lack of visible crystals. It is commonly found in Brazil, India, Madagascar, and the USA. Collectors look for uniform color and high translucency.