mineral

Quartz Geode or Druzy Quartz in Host Rock

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to clear with brownish iron staining; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to clear with brownish iron staining
Luster: Vitreous (glassy) to greasy

Identified June 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the precipitation of silica from hydrothermal fluids or groundwater within cavities of volcanic or sedimentary rocks. The iron oxides (brownish areas) are likely late-stage mineral deposits or weathering products.

Uses & applications

Used primarily for mineral collecting, as decorative stones, and in the production of glass, ceramics, and abrasives. High-purity quartz is also essential in electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. When crystals grow in a cavity like this, it is often referred to as a geode or a 'vug.'

Field identification & locations

Identify in the field by its hardness (it should scratch glass), glassy luster on fresh surfaces, and lack of cleavage. Commonly found in riverbeds, mountain ranges, and volcanic fields globally.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

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metamorphic

Gypsum (variety Selenite or Alabaster)

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Mineral

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Nephrite

Mineral/Rock

Granite

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igneous