gemstone

Tumbled Agate

Silicon Dioxide (Quartz variety: Chalcedony)

Hardness of 6.5 to 7 on the Mohs scale, translucent to opaque, waxy to vitreous luster, microcrystalline crystal structure, conchoidal fracture with no true cleavage, specific gravity of 2.58 to 2.64.

Identified August 3, 2026More gemstone →

Explore Tumbled 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

Formed by the deposition of silica from groundwater in the cavities of igneous and sedimentary rocks, often developing in concentric layers over millions of years.

Uses & applications

Widely used in jewelry, ornamental carvings, polished display stones, and metaphysical collections.

Geological facts

Agate has been used since ancient times (dating back to the Neolithic period) for seals, amulets, and adornments. The name comes from the Achates River in Sicily where agates were found in antiquity.

Field identification & locations

Can be identified by its waxy luster, hardness, and often banded appearance (though tumbled pieces may show cloudy or mottled patterns). Commonly found worldwide, notably in Brazil, India, Madagascar, and the United States.

Other gemstone specimens

See all

Gemstone Ring

N/A - Set piece of jewelry, likely Amethyst or Garnet with Diamond or CZ

gemstone

Diamond and Gold Jewelry

Carbon (Diamond) / Au (Gold)

gemstone

Ammolite

Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)

mineral

Cubic Zirconia (simulant) or Diamond

ZrO2 (Cubic Zirconia) or C (Diamond)

gemstone

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

sedimentary

Black Opal Ring (Carved Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

gemstone