mineral and sedimentary

Quartz, Sandstone, and Siltstone specimens

Silicon Dioxide (SiO2) and Clastic Sedimentary Rocks

AI-generated identification · may be incorrect

Hardness: 7 for quartz, 6-7 for sandstone. Color: milky white, tan, and reddish-brown. Luster: vitreous to earthy. Structure: crystalline quartz and granular sedimentary matrix.

Hardness: 7 for quartz, 6-7 for sandstone
Color: milky white, tan, and reddish-brown
Luster: vitreous to earthy

Identified June 17, 2026More mineral and sedimentary →

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Physical properties

Hardness: 7 for quartz, 6-7 for sandstone. Color: milky white, tan, and reddish-brown. Luster: vitreous to earthy. Structure: crystalline quartz and granular sedimentary matrix.

Formation & geological history

The milky quartz likely formed in hydrothermal veins. The sandstone and siltstone formed through the lithification of sand and silt deposits over millions of years, with the red hue indicating iron oxide presence.

Uses & applications

Primarily for educational collecting, decorative landscaping, and basic construction materials.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. Red sandstone often gets its color from hematite staining, common in terrestrial depositional environments.

Field identification & locations

Identify by scratching glass (quartz will scratch it) and looking for visible grains in the sedimentary pieces. Commonly found in riverbeds, mountains, and deserts.