Quartz Pebble
Silicon Dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (though not visible in tumbled form); Cleavage: None, exhibits conchoidal fracture.
Formation & Geological History
Formed via crystallization from silica-rich hydrothermal fluids or within cooling magma. This specific specimen has been Rounded through fluvial (river) or coastal erosion processes, likely over several thousand years.
Uses & Applications
Used in construction, glassmaking, and as an abrasive. Polished pebbles are often used in landscaping, water features, and pocket stones for meditation.
Geological Facts
Quartz is the second most abundant mineral in Earth's continental crust. When crystals are found in caves or veins, they grow in distinct prisms, but most surface specimens are found as smooth pebbles like this one due to weathering.
Field Identification & Locations
Identify in the field by its hardness (will scratch glass) and lack of cleavage planes. Found globally in riverbed gravels, beaches, and glacial deposits.
Identified on: 4/23/2026
Mode: Standard