metamorphic or igneous

Quartzite or Quartz pebble

SiO2 (Silicon dioxide) with impurities

AI-generated identification · may be incorrect

Hardness: 7, Color: white/clear with orange/red/brown iron staining, Luster: vitreous to waxy, Crystal structure: microcrystalline or massive, Cleavage: none, Specific gravity: 2.65

Identified August 25, 2026More metamorphic or igneous →

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Physical properties

Hardness: 7, Color: white/clear with orange/red/brown iron staining, Luster: vitreous to waxy, Crystal structure: microcrystalline or massive, Cleavage: none, Specific gravity: 2.65

Formation & geological history

Formed from sandstone undergoing heat and pressure (quartzite) or from hydrothermal veins (vein quartz). The rounded shape indicates extensive weathering and tumbling in a river or coastal environment. The reddish-brown colors are due to iron oxide (rust) staining.

Uses & applications

Commonly collected by rockhounds, sometimes tumbled for lapidary purposes. Large deposits are used as aggregate in construction.

Geological facts

Quartz is the most abundant and widely distributed mineral found at Earth's surface. The orange-brown staining is very common in river rocks and is caused by groundwater carrying dissolved iron.

Field identification & locations

Easily identified by its hardness (can scratch glass), lack of cleavage, and conchoidal fracture. Often found in riverbeds, beaches, and glacial deposits.