$Green-gray banded agate (likely polished chalcedony) (Chalcedony, microcrystalline quartz (SiO₂); banding may be quartz-filled fractures) — mineral$

mineral

Green-gray banded agate (likely polished chalcedony)

Chalcedony, microcrystalline quartz (SiO₂); banding may be quartz-filled fractures

AI-generated identification · may be incorrect

Typically Mohs 6.5–7, vitreous to waxy luster, and no visible cleavage. The specimen is opaque green-gray with pale, straight vein-like bands; its exact identity cannot be confirmed from the image alone.

Identified October 14, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids deposit microscopic quartz in cavities or fractures, commonly in volcanic rocks. The image does not establish its geological age or locality.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; common material for lapidary collecting.

Geological facts

Agate is a variety of banded chalcedony; pale lines may be mineral-filled cracks rather than natural concentric agate bands.

Field identification & locations

Look for a hard, smooth surface and waxy luster; agate typically resists scratching by a steel knife. Similar material occurs worldwide, especially in volcanic terrains; the visible bands alone are not diagnostic.