Quartz (likely Herkimer Diamond style)

Physical Properties

Hardness: 7 on Mohs scale; Color: Colorless to white/gray; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & Geological History

Formed in cavities (vugs) within sedimentary rock (specifically dolostone) through the precipitation of silica from hydrothermal fluids during the Cambrian period.

Uses & Applications

Used in jewelry (especially 'Herkimer Diamonds'), industrial abrasives, glassmaking, and valued by mineral collectors for its natural clarity and facets.

Geological Facts

The specimen resembles a 'Herkimer Diamond', which are not actual diamonds but double-terminated quartz crystals from New York. They are famous for having 18 natural facets and extreme clarity.

Field Identification & Locations

Identify by its hardness (will scratch glass), double-termination (pointed at both ends), and glassy luster. Commonly found in Herkimer County, NY, and similar quartz-rich regions globally.

Identified on: 5/1/2026

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