mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Hardness: 7 on Mohs scale; Color: Milky white with reddish-brown or orange streaks; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (often found as water-worn pebbles); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white with reddish-brown or orange streaks
Luster: Vitreous to waxy

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids deposit in veins or cavities. The reddish staining is caused by iron oxide (hematite or limonite) leaching into the micro-fractures of the quartz over geological time. This specific specimen is a beach pebble, indicating it has been rounded by wave action and erosion.

Uses & applications

Used primarily as decorative gravel, in lapidary work for tumbled stones, and as metaphysical 'healing' crystals. Due to its durability, it can also be found in industrial glassmaking and construction aggregates.

Geological facts

Also known as 'Eisenkiesel' in German, meaning 'iron pebble.' It is one of the most common minerals found on beaches worldwide because quartz is highly resistant to both chemical and mechanical weathering.

Field identification & locations

Identify in the field by its ability to scratch glass and the presence of rusty red/orange veins that do not wash off. Found globally in riverbeds and on coastlines. Collectors should look for unique banding or translucency.

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