mineral

Iron-stained quartz geode

Mostly microcrystalline and crystalline quartz (SiO₂), with iron-oxide staining; exact identification is uncertain from the photo

AI-generated identification · may be incorrect

Pale gray-white, translucent to opaque quartz crust surrounding rusty-brown cavities; vitreous to dull luster. Quartz is Mohs 7, trigonal, with no cleavage and conchoidal fracture; iron oxides cause the brown coloration.

Identified October 13, 2026More mineral →

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Physical properties

Formation & geological history

Silica-rich fluids deposited quartz in cavities or fractures, while later oxidation stained it with iron oxides. The specimen’s age and precise geological setting cannot be determined from the image.

Uses & applications

Collected as a display specimen; quartz is also used in glassmaking, abrasives, electronics, and jewelry.

Geological facts

The rusty colors commonly come from hematite or goethite rather than from the quartz itself.

Field identification & locations

Look for hard, glassy quartz surfaces and irregular cavity walls; quartz scratches glass, unlike many softer look-alikes. Quartz geodes and mineralized cavities occur worldwide, including in volcanic and sedimentary settings.