mineral
Quartz (Herkimer Diamond variant)
Silicon Dioxide (SiO2)
Hardness: 7.0 Mohs; Color: Colorless to smoky; Luster: Vitreous; Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.
- Hardness
- 7
- Color
- Colorless to smoky
- Luster
- Vitreous
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Physical properties
Hardness: 7.0 Mohs; Color: Colorless to smoky; Luster: Vitreous; Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.
Formation & geological history
Formed in vugs or cavities within sedimentary rock (specifically Little Falls Dolostone). These crystals grew very slowly from hydrothermal solutions during the Cambrian period, approximately 500 million years ago.
Uses & applications
Used primarily by collectors and in jewelry as 'natural' gemstone points. Also used in metaphysical practices and crystal healing.
Geological facts
Despite the name, they are not diamonds. They are called 'diamonds' because of their natural double-termination (points at both ends) and exceptional clarity. They were first discovered in Herkimer County, New York.
Field identification & locations
Identify by their double-terminated hexagonal shape and high clarity. They are commonly found in dolomitic limestone pockets. Collectors look for 'water-clear' specimens without internal inclusions.
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