Herkimer diamond is the misnomerous name for double-terminated quartz first discovered in exposed outcrops of dolostone at Little Falls in Herkimer County, New York and the Mohawk River Valley. They became largely recognized after workmen discovered them in large quantities while cutting into the Mohawk River Valley dolostone in the late 1700s. 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 lead to the name, Herkimer diamonds. Currently, Herkimer diamonds can be found in large quantity in at least Herkimer, Fulton, and Montgomery counties.

These quartz crystals, which formed extremely slowly in small pockets or vugs, have 18 facets (6 sides) and two terminations. They can be found clear, cloudy, or even containing a variety of rare impurities. Impurities (rare and general) can include clusters, scepters, enhydro, phantom, and bridge crystals. An enhydro contains a water pocket within the crystal, and a phantom is a crystal which contains an image of itself within.

External links

• Mindat with locations
• Website for the New York State Academy of Mineralogy

The crystals referred to unofficially as “Herkimer Diamonds” are officially known as “Little Falls Diamonds” because they are found in a rock formation called “Little Falls Dolostone.”
Some years ago a resident of the village of Herkimer bought one of the diamond mines, and started calling the crystals Herkimer Diamonds, although none are found in the village. They are abundant in the City of Little Falls, and the public library there has a large display of the crystals.

References

• Hirak Rajar Deshe (Kingdom of Diamonds): A film by Satyajit Ray Hirak Rajar Deshe (Kingdom of Diamonds). 1980, India. 118 min, Color, In Bengali with subtitles. Credits. Producer:, Govt. of West Bengal
• TEM imaging and analysis of microinclusions in diamonds: A close File Format: PDF/Adobe Acrobat - View as HTMLInclusions in diamonds provide a unique opportunity to. investigate the mantle rocks in which diamonds are formed. and the fluids from which diamonds
• The Facts - DiamondFacts.org Fact #10:, More than 99% of diamonds are now from conflict free sources and Since diamonds were discovered in Botswana, GDP annual growth rate has
• CNN.com - Discover the science of diamonds - November 20, 2001 Overview: Why are diamonds so valuable? Have students use the article to learn about the formation and mining of diamonds. Diamonds, one of four types of
• Diamonds.net - Home Page Welcome to Diamonds.net - home of RapNet® Diamond Trading Network, INDEX® - Internet Diamond Exchange, Rapaport Diamond Price Sheets, and Rapaport News
• Amazon.com: Optical Properties of Diamond: A Data Handbook: Books Amazon.com: Optical Properties of Diamond: A Data Handbook: Books: AM Zaitsev by AM Zaitsev.
• Diamond - The MIT Press The story of how a mixed-income minority community in Louisiana's Chemical Corridor fought Shell Oil and won.
• GORP - Arkansas State Parks - Crater Of Diamonds State Park History and public use information on diamond mining and campground facilities.