mineral
Polished brown agate pebble
Microcrystalline quartz (SiO₂), likely chalcedony/agate
AI-generated identification · may be incorrectMostly brown and cream with a polished, waxy-to-vitreous luster; quartz has Mohs hardness 7, trigonal crystal structure, and no cleavage. The small, opaque-looking pebble’s exact variety cannot be confirmed from the image.
Identified More mineral →
Explore Polished brown agate pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mostly brown and cream with a polished, waxy-to-vitreous luster; quartz has Mohs hardness 7, trigonal crystal structure, and no cleavage. The small, opaque-looking pebble’s exact variety cannot be confirmed from the image.
Formation & geological history
Silica-rich fluids deposited microscopic quartz in cavities or fractures, later hardened and rounded by weathering or water; agate formation can span many geological ages and settings.
Uses & applications
Used for jewelry, ornaments, and collecting; agate is also used for small decorative objects and, historically, precision tools.
Geological facts
Agate’s characteristic bands form as successive layers of silica, though banding is not clearly visible here.
Field identification & locations
Look for hardness, waxy luster, and possible translucent edges or fine bands; agate is found worldwide in volcanic rocks and stream gravels. Estimated value: about $1–$10 for a small common polished pebble.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous