mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
Hardness: 6.5 to 7 on the Mohs scale. Color: Varies widely, often white, grey, blue, black, or dyed. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None. Specific gravity: 2.6 to 2.7.
- Hardness
- 6
- Color
- Varies widely, often white, grey, blue, black, or dyed
- Luster
- Vitreous to waxy
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 to 7 on the Mohs scale. Color: Varies widely, often white, grey, blue, black, or dyed. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None. Specific gravity: 2.6 to 2.7.
Formation & geological history
Formed mainly by the deposition of silica from groundwater in the cavities of igneous and sedimentary rocks, often occurring as concentric bands in vugs.
Uses & applications
Widely used for ornamental objects, polished slices, coasters, jewelry, and in scientific instruments due to its durability.
Geological facts
Agate is one of the most popular and varied stones used in lapidary arts. Ancient civilizations used it for seals, talismans, and healing amulets.
Field identification & locations
Easily identified by its distinct banded patterns and conchoidal fracture. Found worldwide, particularly in Brazil, Uruguay, India, and parts of the United States.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral