gemstone
Agate
Silicon dioxide (Chalcedony), SiO2
Hardness of 6.5 to 7 on the Mohs scale, vitreous to waxy luster, translucent to opaque transparency, conchoidal fracture, and no true cleavage.
Identified More gemstone →
Explore Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 6.5 to 7 on the Mohs scale, vitreous to waxy luster, translucent to opaque transparency, conchoidal fracture, and no true cleavage.
Formation & geological history
Formed primarily within the cavities of volcanic and metamorphic rocks through the deposition of silica from groundwater solutions, often in concentric bands.
Uses & applications
Used in ornamental objects, jewelry, carvings, industrial bearings, and mortar and pestle sets due to its hardness.
Geological facts
Agate was named by Theophrastus, a Greek philosopher, after the Achates River in Sicily where the stones were first found in antiquity.
Field identification & locations
Easily identified by its characteristic waxy luster and banded or layered appearance. Found globally, particularly in Brazil, Uruguay, and the western United States.
More like this
Other gemstone specimens
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