Porous Quartzite

Physical Properties

Hardness: 7 on Mohs scale; Color: Cream, off-white, light tan; Luster: Vitreous to dull; Structure: Granofelsic with secondary pitting; Cleavage: None/Conchoidal fracture.

Formation & Geological History

Formed through the metamorphism of quartz sandstone under intense heat and pressure. The pits or vugs often result from the weathering out of softer soluble minerals like calcite or the removal of fossil inclusions.

Uses & Applications

Primarily used in construction (crushed stone), as decorative garden stones, or as abrasive materials due to high silica content.

Geological Facts

Quartzite is so tough that it often survives transport in high-energy beach or river environments where other rocks crumble. The holes in this specific specimen are called 'vugs' or are results of differential weathering.

Field Identification & Locations

Identify by its ability to scratch glass and its grainy, sandpaper-like texture that has been fused into a crystalline mass. Common in mountainous regions and glacial deposits.

Identified on: 5/1/2026

Mode: Standard