mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white (milky) crystals; Luster: Vitreous/glassy; Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to white (milky) crystals
Luster: Vitreous/glassy

Identified April 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to white (milky) crystals; Luster: Vitreous/glassy; Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in cavities (vugs) within volcanic or sedimentary rocks. Over time, mineral-rich groundwater seeps into the hollow space, depositing silica crystals that grow inward toward the center.

Uses & applications

Used primarily for display, educational purposes, spiritual/metaphysical uses, and occasionally as raw material for jewelry or as a decorative lapidary item.

Geological facts

Geodes are essentially 'rock bubbles.' While the exterior looks like an ordinary, bumpy rock, the interior can hold massive, pristine crystal clusters that have been protected for millions of years.

Field identification & locations

Identify in the field by looking for rounded, knobby, hollow-sounding rocks that are lighter than they appear. Commonly found in desert regions or limestone beds in places like Morocco, Brazil, and the Midwestern USA.