mineral

Likely polished agate beads

Agate, a banded variety of chalcedony (microcrystalline SiO₂); exact identification is uncertain from the image

AI-generated identification · may be incorrect

The visible beads are glossy, rounded, and dark reddish-brown to nearly black, with possible subtle banding. Agate has Mohs hardness 6.5–7, a trigonal microcrystalline quartz structure, and no cleavage; specific gravity is about 2.6.

Identified October 2, 2026More mineral →

Explore Likely polished agate beads in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Agate forms as silica-rich fluids fill cavities in volcanic rocks, depositing chalcedony in layers. Deposits occur in rocks of many geological ages.

Uses & applications

Beads are used in jewelry and crafts; agate is also used for ornaments and, less commonly, precision components.

Geological facts

Agate is commonly dyed or heat-treated, so bead color alone does not establish the variety.

Field identification & locations

Look for waxy luster and fine, curved bands; a photograph cannot confirm the material or treatment. Agate is found worldwide, including Brazil, Uruguay, India, and the United States.