Yellow Quartzite (Tumbled)

Physical Properties

Hardness: 7 (Mohs scale); Color: Pale yellow to honey gold; Luster: Vitreous to waxy (when polished); Crystal Structure: Hexagonal/Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.63–2.65

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone. High heat and pressure cause quartz grains to recrystallize and fuse together, creating a incredibly hard, dense rock. The yellow color is typically caused by iron oxide inclusions (limonite).

Uses & Applications

Used primarily as decorative stone, aquarium gravel, landscape material, and in tumbled form for crystal healing or pocket stones. High-grade quartzite is also used for building facades and countertops.

Geological Facts

Quartzite is so hard that it can scratch glass and steel. It is frequently mistaken for similar-looking marble, but marble is much softer and will fizz when exposed to acid, whereas quartzite will not.

Field Identification & Locations

Identify in the field by its grainy, sugary texture under a lens and its extreme hardness. It won't be scratched by a knife blade. Commonly found in folded mountain belts and ancient shield regions globally.

Identified on: 4/22/2026

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