mineral

Quartz (Gold-bearing Prospect)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Transparent to milky white with honey-colored staining, Luster: Vitreous to greasy, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified July 6, 2026More mineral →

Explore Quartz (Gold-bearing Prospect) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed in hydrothermal veins where hot, mineral-rich fluids circulate through fractures in the Earth's crust. In this specific region of Northern California, these veins are associated with the Mother Lode gold belt, dating to the Late Jurassic to Early Cretaceous periods.

Uses & applications

Primary source for gold mining historical interest, decorative use, jewelry when containing visible gold, and industrial use in glass and electronics.

Geological facts

The location (39.1°N, 121.6°W) is near Marysville/Yuba City, just west of the famous Sierra Nevada foothills. This area is downstream from the historic Yuba River gold fields. High-luster quartz fragments like this were the 'pathfinders' for 49ers during the California Gold Rush.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. In the Yuba River area, look for iron staining (rusty colors) which often indicates the presence of sulfides or gold. It is commonly found in river gravels as water-worn pebbles or in outcroppings in the foothills.

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