sedimentary
Agate
Silicon Dioxide (SiO2)
Hardness: 6.5-7 on the Mohs scale. Color: Varies widely including white, gray, blue, red, orange, and brown, often in multicolored bands. Luster: Vitreous to dull. Crystal structure: Trigonal (microcrystalline quartz/chalcedony). Cleavage: None. Specific gravity: 2.58-2.64.
- Hardness
- 6
- Luster
- Vitreous to dull
Identified More sedimentary →
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 on the Mohs scale. Color: Varies widely including white, gray, blue, red, orange, and brown, often in multicolored bands. Luster: Vitreous to dull. Crystal structure: Trigonal (microcrystalline quartz/chalcedony). Cleavage: None. Specific gravity: 2.58-2.64.
Formation & geological history
Formed primarily within cavities of volcanic and metamorphic rocks through the slow deposition of silica-rich groundwater solutions over millions of years.
Uses & applications
Used in jewelry, decorative items, ornamental carvings, precision instruments, and lapidary art.
Geological facts
Agate is one of the most popular materials used in hardstone carving and has been used since ancient times for amulets and seals.
Field identification & locations
Identified by its characteristic concentric color banding and waxy luster. Found worldwide, notably in Brazil, Uruguay, India, Madagascar, and the USA.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary