mineral

Ferruginous Quartz

Quartz (Silicon Dioxide) with Iron Inclusion (SiO2 + Fe2O3)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with reddish-brown hematite staining; Luster: Vitreous to waxy; Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous to waxy

Identified March 9, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids crystallize in veins or cavities. The reddish tint is caused by iron oxide (hematite or limonite) staining that occurs during or after the initial crystallization. Most specimens are found in Precambrian to Cenozoic formations.

Uses & applications

Used primarily as decorative garden stones, in lapidary work for cabochons/tumbled stones, and as a collector specimen. High-purity quartz is used in electronics and glass manufacturing, though stained specimens are less desirable for industrial use.

Geological facts

Also commonly known as 'Iron Quartz' or 'Hematoid Quartz.' The red coloration is often just a surface coating or a thin layer within the crystal, often following early growth planes of the quartz crystal.

Field identification & locations

Identify in the field by its high hardness (it will scratch glass), lack of cleavage, and the characteristic rusty-red staining that does not wash off with water. It is a common find in riverbeds and mountainous terrain globally.

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