mineral

Iron-stained quartz crystal

Quartz, silicon dioxide (SiO₂), likely limonite/goethite inclusions or surface staining

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray, cream, and reddish-brown; vitreous luster; hexagonal crystal structure; no cleavage, with conchoidal fracture. The reddish-brown coloration likely comes from iron oxides.

Identified September 4, 2026More mineral →

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Physical properties

Formation & geological history

Quartz commonly crystallizes in hydrothermal veins, cavities, and pegmatites as silica-rich fluids cool; iron staining formed during later weathering and oxidation. The exact geological age and locality cannot be determined from the image.

Uses & applications

Used in glass, electronics, abrasives, and countertops; attractive crystals are collected or used decoratively, though this rough specimen has limited jewelry value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge when mechanically stressed.

Field identification & locations

Identify by its glassy luster, lack of cleavage, conchoidal breakage, and ability to scratch glass; iron staining is common on exposed quartz. Common worldwide, especially in hydrothermal vein districts and pegmatites.