sedimentary
Quartz Geode
Quartz (Silicon Dioxide, SiO2) in a Geode
AI-generated identification · may be incorrectHardness: 7 (Mohs scale), Color: Clear to milky crystals in a brown/grey host rock, Luster: Vitreous/glassy crystals, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Identified More sedimentary →
Explore Quartz Geode in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: Clear to milky crystals in a brown/grey host rock, Luster: Vitreous/glassy crystals, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Formation & geological history
Formed as hollow cavities in sedimentary or volcanic rock that are filled by the slow precipitation of mineral-rich water over millions of years.
Uses & applications
Commonly used for geological study, home decor, metaphysical collecting, and occasionally as a source for small gemstones.
Geological facts
The word geode is derived from the Greek word Geoides, which means earth-like. Unlike vugs, geodes have a hollow interior lined with crystals.
Field identification & locations
Identify in the field by looking for round, bumpy, cauliflower-like nodules that feel lighter than solid rocks of the same size. Commonly found in deserts or river beds.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary