mineral

Quartz geode fragment

Mostly crystalline quartz (SiO₂), possibly with dark iron/manganese oxides or other host-rock minerals

AI-generated identification · may be incorrect

White to gray, glassy crystals lining a small cavity; quartz hardness 7 Mohs, trigonal crystal system, no cleavage, specific gravity about 2.65. The dark outer material appears to be a mineralized rind or host rock.

Identified October 11, 2026More mineral →

Explore Quartz geode fragment in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed as silica-rich fluids deposited quartz crystals in a cavity within host rock; geologic age and exact formation environment cannot be determined from the image.

Uses & applications

Small specimens are mainly used for collecting and display; larger geodes may be cut or polished for decoration and jewelry.

Geological facts

Geodes develop when crystals grow inward from a hollow cavity, often over long periods as mineral-bearing water circulates.

Field identification & locations

The visible inward-facing crystal lining and contrasting outer rind suggest a geode fragment. Similar specimens occur worldwide; confirm quartz by its hardness and lack of cleavage.