mineral
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geode
Hardness: 7 on Mohs scale; Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Color
- Clear to white
- Luster
- Vitreous (glassy)
Identified More mineral →
Explore Quartz Geode in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.
Formation & geological history
Formed in the cavities of sedimentary or volcanic rocks. Mineral-rich groundwater seeps into hollow vesicles or bubbles, and over millions of years, crystals precipitate and grow inward towards the center.
Uses & applications
Primarily used for decorative purposes, crystal healing collections, educational geological specimens, and occasionally as minor birthstone jewelry materials.
Geological facts
The word geode comes from the Greek word 'Geoides' meaning earth-like. Unlike a cluster, a geode must have a hollow cavity inside where crystals have grown. Identifying a geode before it is cracked open often involves looking for round, bumpy, potato-like exterior rocks that feel unusually light for their size.
Field identification & locations
Identify in the field by looking for nodular rock shapes with a textured outer rind. Common locations include Morocco, Brazil, and the Midwestern United States (Keokuk region). Collectors look for well-defined, undamaged crystal terminations.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock