mineral

Agate

Silicon Dioxide (Chalcedony), SiO2

AI-generated identification · may be incorrect

Hardness: 6.5 to 7 on the Mohs scale. Color: Varies widely, often white, grey, blue, black, or dyed. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None. Specific gravity: 2.6 to 2.7.

Hardness: 6
Color: Varies widely, often white, grey, blue, black, or dyed
Luster: Vitreous to waxy

Identified July 31, 2026More mineral →

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Physical properties

Formation & geological history

Formed mainly by the deposition of silica from groundwater in the cavities of igneous and sedimentary rocks, often occurring as concentric bands in vugs.

Uses & applications

Widely used for ornamental objects, polished slices, coasters, jewelry, and in scientific instruments due to its durability.

Geological facts

Agate is one of the most popular and varied stones used in lapidary arts. Ancient civilizations used it for seals, talismans, and healing amulets.

Field identification & locations

Easily identified by its distinct banded patterns and conchoidal fracture. Found worldwide, particularly in Brazil, Uruguay, India, and parts of the United States.