mineral

Quartz (Chert/Quartzite)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs), Color: Tan to light brown, Luster: Vitreous to waxy, Crystal structure: Trigonal/Microcrystalline, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified July 17, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs), Color: Tan to light brown, Luster: Vitreous to waxy, Crystal structure: Trigonal/Microcrystalline, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Formation & geological history

Formed by the accumulation of silica-rich fluids or the lithification of silica-rich marine sediments. This specific specimen appears to be a weathered fragment of common quartz or chert found in diverse geological environments.

Uses & applications

Industrial use in glassmaking, construction aggregates, and historically for making stone tools. It is also a very common collector's item for beginners.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Chert, a variety of quartz, was the primary material used by prehistoric humans for arrowheads and scrapers because of its sharp conchoidal edges.

Field identification & locations

Identified in the field by its hardness (it will scratch glass) and lack of cleavage. Found worldwide in nearly all geological settings. Look for the distinctive waxy luster on freshly broken surfaces.