mineral

Quartz (River Pebble) and Chert/Jasper

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Translucent white to tan (quartz) and brownish-red (chert). Luster: Vitreous to waxy. Crystal structure: Hexagonal/Trigonal. Cleavage: None (conchoidal fracture).

Hardness: 7 on Mohs scale
Color: Translucent white to tan (quartz) and brownish-red (chert)
Luster: Vitreous to waxy

Identified July 5, 2026More mineral →

Explore Quartz (River Pebble) and Chert/Jasper in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale. Color: Translucent white to tan (quartz) and brownish-red (chert). Luster: Vitreous to waxy. Crystal structure: Hexagonal/Trigonal. Cleavage: None (conchoidal fracture).

Formation & geological history

Formed through hydrothermal or igneous processes (Quartz) and chemical sedimentary precipitation (Chert). These specific specimens are water-worn river pebbles likely millions of years old, rounded by fluvial erosion.

Uses & applications

Common quartz is used for abrasives and glassmaking; these specific pebbles are primarily collected for hobbyist tumbling, lapidary practice, or decorative landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Chert was historically used by indigenous peoples for stone tools and arrowheads due to its predictable conchoidal fracture leading to sharp edges.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. These are common in river beds, beaches, and glacial till. Collectors look for unique banding or clarity in similar specimens.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock

Granite

Granite (Phaneritic intrusive igneous rock)

igneous