mineral

Banded Agate (specifically Gobi Eyes or Eye Agate)

Silicon Dioxide (SiO2) - Variety of Chalcedony

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale), Color: Concentric bands of white, brown, grey, and black, Luster: Waxy to vitreous, Crystal structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture, Specific gravity: 2.60-2.65

Hardness: 6

Identified May 27, 2026More mineral →

Explore Banded Agate (specifically Gobi Eyes or Eye Agate) in the encyclopedia →

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Physical properties

Formation & geological history

Formed as secondary deposits in volcanic cavities or vesicles where silica-rich groundwater rhythmically precipitates layers of chalcedony over millions of years. Many eye agates date back to the Cretaceous or Neogene periods.

Uses & applications

Used primarily in lapidary arts for jewelry, decorative carvings, metaphysical 'eye stones' for protection, and as valued specimens for geological collectors.

Geological facts

The 'eye' pattern is created when silica layers deposit in a circular or spherical fashion. The Gobi Desert is famous for these desert-varnished 'Alashan' agates which have been naturally weathered by sand and wind.

Field identification & locations

Identify by its distinct concentric circular 'eye' banding and its ability to scratch glass. This specific specimen has been carved into a faceted geometric shape to showcase the internal patterns.