sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
Hardness of 7 on the Mohs scale, typically brown or grey exterior with crystalline quartz interiors, vitreous luster, trigonal crystal system, specific gravity around 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 of 7 on the Mohs scale, typically brown or grey exterior with crystalline quartz interiors, vitreous luster, trigonal crystal system, specific gravity around 2.65.
Formation & geological history
Formed in hollow spaces in sedimentary or volcanic rocks where silica-rich groundwater circulates and deposits minerals over millions of years.
Uses & applications
Popular as collector specimens, decorative items, and in crystal healing practices.
Geological facts
Geodes start as nodules or cavities in rock, often containing fossils, roots, or mineral lumps that eventually dissolve or hollow out, leaving space for crystal growth.
Field identification & locations
Easily identified by their rounded, knobby exterior and sparkling crystalline interior when broken open. Found worldwide, particularly in desert regions and volcanic deposits.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary