mineral

Tumbled Grey Agate

Silicon Dioxide (Chalcedony variety), SiO2

AI-generated identification · may be incorrect

Hardness: 6.5-7 on the Mohs scale; Color: Grey with mottled or banded patterns; Luster: Waxy to vitreous; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.60-2.65

Hardness: 6
Color: Grey with mottled or banded patterns
Luster: Waxy to vitreous

Identified August 1, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on the Mohs scale; Color: Grey with mottled or banded patterns; Luster: Waxy to vitreous; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.60-2.65

Formation & geological history

Formed in the cavities of volcanic and metamorphic rocks through the deposition of silica-rich groundwater over millions of years.

Uses & applications

Used primarily in lapidary arts, tumbled stones, jewelry, decorative carvings, and metaphysical practices.

Geological facts

Agate has been used by humans for thousands of years, dating back to the Neolithic period, for amulets, seals, and ornaments. The grey variety is often associated with grounding and emotional balance.

Field identification & locations

Identified by its waxy luster, microcrystalline structure, conchoidal fracture, and resistance to scratching by steel. Common worldwide, particularly in Brazil, India, Madagascar, and the USA.