sedimentary
Quartz Vein in River Siltstone
Crystalline Quartz (SiO2) in Siliclastic Matrix
Hardness: 7 (quartz), 3-5 (matrix); Color: White to translucent tan vein, greyish-brown host rock; Luster: Vitreous/Glassy; Structure: Hexagonal crystals within a river-worn grain.
- Hardness
- 7 (quartz), 3-5 (matrix)
- Color
- White to translucent tan vein, greyish-brown host rock
- Luster
- Vitreous/Glassy
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Physical properties
Hardness: 7 (quartz), 3-5 (matrix); Color: White to translucent tan vein, greyish-brown host rock; Luster: Vitreous/Glassy; Structure: Hexagonal crystals within a river-worn grain.
Formation & geological history
Formed through hydrothermal processes where silica-rich fluids filled fractures in existing sedimentary rock, followed by river erosion that smoothed the specimen into a cobble.
Uses & applications
Collecting specimen, educational use, and decorative landscaping material.
Geological facts
Quartz veins often form during tectonic events when pressure forces water out of minerals, carrying dissolved silica into cracks where it precipitates as crystals.
Field identification & locations
Identify by looking for a hard, white crystalline band that scratches glass, embedded in a softer, fine-grained host rock. Common in riverbeds and mountainous terrain.
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