mineral
Banded Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 (Mohs scale), Color: Brownish-grey with visible curved banding, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (trigonal) microcrystalline, Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.64
- Hardness
- 6
Identified More mineral →
Explore Banded 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: Brownish-grey with visible curved banding, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (trigonal) microcrystalline, Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.64
Formation & geological history
Formed as secondary deposits in volcanic rock cavities (amygdules) or sedimentary veins. Silica-rich groundwater precipitates layers of microscopic quartz crystals over long periods.
Uses & applications
Used widely in lapidary arts, jewelry, decorative carvings, and industrially for precision pendulums, mortars and pestles due to its hardness.
Geological facts
Agate is named after the Achates River in Sicily where it was first discovered in ancient times. The banding patterns represent different stages of silica deposition in the host rock cavity.
Field identification & locations
Identified by its distinctive curved layers and translucent edges. It can be found in gravel beds, volcanic outcrops, and along shorelines of the Great Lakes (Lake Superior Agates).
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Schist
Schist
Metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock