mineral
Agate (Polished Slice)
Silicon Dioxide (SiO2)
Hardness: 6.5 - 7 on Mohs scale. Color: Translucent gray, brown, and tan shades with subtle faint banding. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline/cryptocrystalline quartz). Cleavage: None, exhibits conchoidal fracture.
- Hardness
- 6
- Luster
- Vitreous to waxy
Identified More mineral →
Explore Agate (Polished Slice) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5 - 7 on Mohs scale. Color: Translucent gray, brown, and tan shades with subtle faint banding. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline/cryptocrystalline quartz). Cleavage: None, exhibits conchoidal fracture.
Formation & geological history
Formed in cavities within volcanic rocks or ancient sedimentary formations where silica-rich groundwater deposited successive layers of microcrystalline quartz over millions of years.
Uses & applications
Popular for decorative items, coasters, lapidary art, jewelry, wire-wrapping, and educational rock collections.
Geological facts
Agate was named by the ancient Greek philosopher Theophrastus after the Dirillo (Achates) River in Sicily, where specimens were found over two thousand years ago.
Field identification & locations
Identify by its waxy luster, hardness (scratches glass), smooth polished cut surface, and characteristic concentric or semi-translucent layering near the rim. Commonly found in Brazil, Uruguay, Madagascar, and the USA.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock