
mineral
Agate
Chalcedony (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs scale), Color: Various, often banded; this specimen is grayish/translucent with brownish/reddish iron oxide inclusions, Luster: Waxy to vitreous, Crystal structure: Cryptocrystalline, Cleavage: None, Specific gravity: 2.58-2.64
- Hardness
- 6
- Color
- Various, often banded
Identified More mineral →
Explore Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Various, often banded; this specimen is grayish/translucent with brownish/reddish iron oxide inclusions, Luster: Waxy to vitreous, Crystal structure: Cryptocrystalline, Cleavage: None, Specific gravity: 2.58-2.64
Formation & geological history
Forms primarily in cavities of eruptive rocks or ancient lavas from silica-rich fluids. Can also form in sedimentary environments. Age varies widely depending on the host rock.
Uses & applications
Used in jewelry, lapidary arts, ornaments, and as a collector's stone. Hardness makes it suitable for some industrial uses like precision pendulum bearings or mortar and pestles.
Geological facts
Agate is a variety of chalcedony characterized by its fineness of grain and brightness of color. It is named after the Achates River (now Dirillo) in Sicily, where it was first found.
Field identification & locations
Identified by its waxy luster, translucency, and often banded appearance (though not always prominent). Commonly found worldwide in volcanic areas. For collectors, look for unique patterns and colors. Wetting the stone (as seen in the image) often brings out colors and patterns.