mineral

Tumbled banded agate (likely carnelian/white agate)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent white to pale gray with orange-brown, yellow, and blue-gray bands; waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage. The rounded, polished shape indicates a tumbled specimen.

Identified August 24, 2026More mineral →

Explore Tumbled banded agate (likely carnelian/white agate) 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 when silica-rich groundwater fills cavities in volcanic rocks, depositing chalcedony and quartz in successive bands. Individual layers may form over long periods, commonly in Cenozoic basaltic terrains.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and lapidary collections; its durability makes it suitable for jewelry and decorative objects.

Geological facts

Color bands commonly reflect iron oxides and other trace impurities. Agate is often dyed, though these muted natural colors appear consistent with untreated material.

Field identification & locations

Identify by hardness, waxy translucency, curved banding, and lack of cleavage; common sources include Brazil, Uruguay, India, Mexico, and the United States. A scratch test with steel is not definitive; quartz should resist ordinary steel.