mineral

Herkimer Diamond

Quartz (Silicon Dioxide - SiO2)

Hardness: 7.5 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous; Crystal Structure: Hexagonal (doubly terminated); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Hardness: 7
Color: Colorless/Transparent
Luster: Vitreous

Identified June 23, 2026More mineral →

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Physical properties

Hardness: 7.5 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous; Crystal Structure: Hexagonal (doubly terminated); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Formation & geological history

Formed in cavities (vugs) within Little Falls Dolostone during the Cambrian period (~500 million years ago) through hydrothermal precipitation.

Uses & applications

Highly prized for mineral collecting, jewelry (rings, pendants), and metaphysical use. Industrial quality quartz is used in glass and electronics.

Geological facts

Herkimer Diamonds are not actually diamonds but are exceptionally clear quartz crystals. They are famous for being 'doubly terminated,' meaning they have natural points at both ends.

Field identification & locations

Identified by their double points and exceptional clarity compared to standard quartz. Most commonly found in Herkimer County, New York. Collectors look for 'vugs' or pockets in exposed dolostone.