Quartz Pebble (Iron-Stained)

Physical Properties

Hardness: 7 (Mohs scale); Color: Yellow-tan, orange, and white (iron-stained); Luster: Vitreous to greasy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Formed through hydrothermal processes or as a secondary mineral in igneous and metamorphic rocks. This specific specimen has been tumbled and rounded by water action in a river or creek bed, and stained yellow/orange by iron oxides (limonite/hematite).

Uses & Applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as a raw material for silicon. In this pebble form, it is common as landscaping gravel or for lapidary tumbling.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz'. Iron staining is very common in quartz pebbles, giving them a 'citrine-like' honey appearance without being true gem citrine.

Field Identification & Locations

Identify by its hardness (it will scratch glass) and lack of cleavage (breaks like glass). Commonly found in riverbeds, glacial tills, and beaches. Collectors often look for more translucent or crystal-dense pieces for tumbling.

Identified on: 4/13/2026

Mode: Standard