gemstone
Agate
Silicon dioxide (Chalcedony), SiO2
AI-generated identification · may be incorrectMohs hardness of 6.5-7, waxy to vitreous luster, microcrystalline crystal structure, and exhibits distinctive curved concentric banding in various colors.
Identified More gemstone →
Explore Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6.5-7, waxy to vitreous luster, microcrystalline crystal structure, and exhibits distinctive curved concentric banding in various colors.
Formation & geological history
Forms by the deposition of silica from groundwater in cavities of igneous and sedimentary rocks, often over millions of years.
Uses & applications
Widely used in jewelry, decorative carvings, tumbling, and precision instruments due to its durability and aesthetic banding.
Geological facts
Agate was highly prized in the ancient world as a talisman and for making intricately carved signet rings and cameos.
Field identification & locations
Identified by its waxy luster, conchoidal fracture, and characteristic translucent color bands; found worldwide in volcanic rock cavities.
More like this
Other gemstone specimens
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Gemstone Ring
N/A - Set piece of jewelry, likely Amethyst or Garnet with Diamond or CZ
gemstone
Amber
Succinite (Organic Gemstone)
mineral
Diamond and Gold Jewelry
Carbon (Diamond) / Au (Gold)
gemstone
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Pearl necklace
Pearl, primarily aragonite (CaCO₃) and conchiolin
gemstone