metamorphic

Iron-stained quartzite or ironstone pebble

Quartzite (mostly SiO₂) with iron-oxide/hydroxide minerals, likely hematite/goethite

AI-generated identification · may be incorrect

Hardness about 6.5–7 for the quartz-rich matrix; dark olive-brown, fine-grained, and weakly waxy to dull luster, with a sparkly metallic-looking crust. Quartz has no cleavage and conchoidal fracture; the apparent crystals may be iron oxides or drusy quartz.

Identified September 21, 2026More metamorphic →

Explore Iron-stained quartzite or ironstone pebble 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

Likely a water-worn cobble derived from metamorphosed sandstone or iron-rich silica rock, later coated or cemented by iron oxides in a weathering or hydrothermal environment. Exact age and locality cannot be determined from the photograph.

Uses & applications

Primarily a curiosity, lapidary, or collection specimen; iron-rich quartzite can be used as decorative stone or aggregate, though this small piece has no practical industrial value.

Geological facts

The brown coloration commonly comes from goethite and limonite weathering products, while darker metallic areas may contain hematite or magnetite. A streak, magnet test, and hardness test would substantially improve identification.

Field identification & locations

Commonly encountered in river gravels and iron-rich terrains worldwide; it should resist scratching by a steel knife if quartzite. Avoid damaging tests if it is a valued specimen.