mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Hardness: 7 (Mohs scale); Color: Yellowish-brown to orange from iron staining, translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Yellowish-brown to orange from iron staining, translucent
Luster: Vitreous to greasy

Identified April 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal solutions or cooling magma rich in silica. The yellow/brown color is due to the infiltration of iron-rich groundwater or limonite/hematite inclusions during or after crystallization.

Uses & applications

Used primarily as decorative stones, in landscaping, and as a collector's specimen. High-quality quartz is used in electronics and glass-making.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz is often mistaken for citrine, though citrine's color is within the crystal lattice rather than a surface staining or inclusion.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and the characteristic conchoidal fracture. Commonly found in riverbeds, gravel pits, and mountain ranges globally.

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Mineral/Rock

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Metamorphic Rock

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mineral