Quartzite Pebbles

Physical Properties

Hardness: 7 on Mohs scale; Color: white, cream, tan, and light pink; Luster: vitreous to waxy; Structure: non-foliated granoblastic; Cleavage: none (conchoidal fracture); Specific gravity: 2.6-2.7

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone. Under high heat and pressure, quartz grains recrystallize and fuse together. These specific specimens are water-worn river pebbles, rounded by mechanical erosion over thousands of years.

Uses & Applications

Used widely in landscaping, construction (as aggregate), aquarium decor, and sometimes as low-cost tumbled gemstones for hobbyists.

Geological Facts

Quartzite is so durable that it often survives the intense weathering processes that destroy other rocks, which is why it is often found as smooth pebbles in riverbeds and on beaches.

Field Identification & Locations

Identify in the field by its hardness (it will easily scratch glass) and its sugary, crystalline texture when broken. It is found globally in mountainous regions and fluvial deposits.

Identified on: 4/19/2026

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