metamorphic

Likely iron-oxide–stained quartz or quartzite pebble

Quartz (SiO₂), possibly as quartzite; exact identification is uncertain from the image

AI-generated identification · may be incorrect

Small, opaque yellow-brown pebble with an uneven surface and dull to slightly vitreous luster. Quartz has Mohs hardness 7 and a trigonal crystal structure; quartzite is interlocking quartz grains and has no cleavage.

Identified September 23, 2026More metamorphic →

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Physical properties

Formation & geological history

Quartz forms in many geological settings; quartzite forms when quartz-rich sandstone is recrystallized during metamorphism. The pebble’s age and source cannot be determined from the photograph.

Uses & applications

Commonly collected as a hand specimen; quartz and quartzite are also used in glassmaking, abrasives, and construction aggregate.

Geological facts

Yellow-brown coloring may come from iron-oxide staining, but color alone cannot confirm the material.

Field identification & locations

Check for a glassy appearance and ability to scratch ordinary glass; a fresh broken surface or hardness test would help distinguish quartz from softer lookalikes. Quartz and quartzite occur worldwide.