- Herkimer diamond
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Herkimer diamond is a generic name for a double-terminated quartz crystal discovered within exposed outcrops of dolostone in and around Herkimer County, New York and the Mohawk River Valley. Because the first discovery sites were in the village of Middleville and in the city of Little Falls, respectively, the crystal is also known as a Middleville diamond or a Little Falls diamond.[1]
Herkimer diamonds became largely recognized after workmen discovered them in large quantities while cutting into the Mohawk River Valley dolostone in the late 18th century. Geologists discovered exposed dolostone in Herkimer County and began mining there. The popularity of mining for double-terminated quartz in the Herkimer County outcroppings is what led to the name, Herkimer diamonds. Currently, Herkimer diamonds can be found in large quantity in at least Herkimer, Fulton, and Montgomery counties, and double-pointed quartz crystals have also been found in abundance, in Tibet and Afghanistan as well as in other countries.
Many of the New York crystals are known for their extreme clarity, and Wiccan and New Age belief systems often ascribe specific occult properties and a wide variety of mystical powers to them.
These quartz crystals, which geologists theorize formed extremely slowly in small solution cavities or vugs, have 18 facets (6 sides) and two terminations. There are also larger cavities that are several feet in diameter that are called "pockets". They can be found clear, cloudy, smoky or even containing a variety of rare impurities. Impurities (rare and general) can include clusters, scepters, enhydro (properly called fluid inclusions), phantom, and bridge crystals. A fluid inclusion contains a water pocket (plus methane or oil, and rarely a crystal) within the crystal, a phantom is a crystal which contains an image of itself within, a skeletal crystal contains a series of crystal edge outlines inside the crystal and a hopper crystal has its faces replaced by a step like pattern.
References
- ^ http://www.mindat.org/min-1877.html Mindat with locations
External links
- Website for the New York State Academy of Mineralogy
- Prospecting for Herkimer Diamonds
- HerkimerHistory.com
Crystalline - Coesite
- Cristobalite
- Moganite
- Quartz
- Seifertite
- Stishovite
- Tridymite
Cryptocrystalline Amorphous Miscellaneous Notable varieties - Amethyst
- Ametrine
- Citrine
- Milky quartz
- Rose quartz
- Smoky quartz
- Shocked quartz
Categories:- Quartz varieties
- Herkimer County, New York
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