sedimentary

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

AI-generated identification · may be incorrect

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

Identified May 3, 2026More sedimentary →

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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.