mineral

Polished agate nodule

Agate, microcrystalline quartz (SiO₂), a variety of chalcedony

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; orange-brown, gray, and white with waxy to vitreous luster and fine, cryptocrystalline quartz. The polished face shows irregular color bands; no visible cleavage.

Identified October 7, 2026More mineral →

Explore Polished agate nodule in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness about 6.5–7 Mohs; orange-brown, gray, and white with waxy to vitreous luster and fine, cryptocrystalline quartz. The polished face shows irregular color bands; no visible cleavage.

Formation & geological history

Silica-rich groundwater deposited chalcedony in cavities and fractures, commonly in volcanic rocks; agate forms across many geological ages.

Uses & applications

Used for cabochons, beads, ornaments, and small decorative objects; also collected as a polished specimen.

Geological facts

Agate is prized for its diverse colors and banding, though this specimen’s bands are subtle and partly obscured by rough exterior material.

Field identification & locations

Identify by its very fine quartz texture, hardness, waxy sheen, and often translucent or banded zones. Agates occur worldwide, especially in volcanic regions; the exact locality cannot be determined from the image.