mineral

Quartz Geode Segment

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to milky with yellow staining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Translucent white to milky with yellow staining
Luster: Vitreous to waxy

Identified June 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed via hydrothermal precipitation in rock cavities. Mineral-rich water seeps into voids in volcanic or sedimentary rock, slowly depositing silica layers over thousands of years. Usually found in formations from various geological ages, often Cretaceous or Tertiary.

Uses & applications

Used primarily for interior decoration, specimen collecting, educational purposes, and occasionally in the manufacture of glass or electronics if high purity. High-quality pieces are used in lapidary work.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Geodes are unique because they look like ordinary rocks on the outside but contain hollow centers lined with crystals on the inside.

Field identification & locations

Identify by its characteristic crystalline structure inside a rounded outer rind. It will scratch glass easily. Commonly found in desert environments, riverbeds, and limestone-heavy regions worldwide.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral