mineral
Chalcedony (likely agate)
Microcrystalline quartz, SiO₂; agate is banded chalcedony
AI-generated identification · may be incorrectTranslucent gray with honey-brown edges and a waxy to vitreous luster; hardness about 6.5–7 Mohs, trigonal quartz structure, no cleavage, and conchoidal fracture. The image does not show clear banding, so agate identification is uncertain.
Identified More mineral →
Explore Chalcedony (likely agate) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Translucent gray with honey-brown edges and a waxy to vitreous luster; hardness about 6.5–7 Mohs, trigonal quartz structure, no cleavage, and conchoidal fracture. The image does not show clear banding, so agate identification is uncertain.
Formation & geological history
Silica-rich fluids deposited quartz in cavities and fractures, commonly in volcanic rocks; chalcedony formed across many geological ages and settings.
Uses & applications
Used for carvings, beads, cabochons, ornamental objects, and as a collector specimen.
Geological facts
Chalcedony is quartz made of crystals too small to distinguish unaided; agate is its distinctly banded variety.
Field identification & locations
Look for waxy translucence and curved, shell-like fracture surfaces; agate is typically confirmed by visible bands. Chalcedony occurs worldwide, including Brazil, Uruguay, India, and the western United States.
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