
mineral
Bull Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale; Color: Opaque white to cream with brownish iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal (often massive in boulders); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Opaque white to cream with brownish iron staining
- Luster
- Vitreous to greasy
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Physical properties
Hardness: 7 on Mohs scale; Color: Opaque white to cream with brownish iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal (often massive in boulders); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed from hydrothermal solutions cooling in veins and fractures within host rocks or as large masses in pegmatites. This specimen likely weathered out of a larger quartz vein over millions of years.
Uses & applications
Used in landscaping (decorative garden stones), crushed for industrial silicon production, glass manufacturing, and as an abrasive.
Geological facts
Milky quartz gets its white color from tiny fluid inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz found on Earth's surface.
Field identification & locations
Identify by its 'milky' white appearance and superior hardness (it will easily scratch glass and steel). Commonly found in areas with metamorphic or igneous activity; look for heavy, white outcrops in hilly terrain.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous