Where is Herkimer Diamond Quartz found?
Quartz (SiO2) with hydrocarbon inclusions
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Open the appHerkimer Diamond Quartz occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Herkimer Diamond Quartz
Herkimer County, New York, USA
The primary and namesake locality. Found in numerous mines and collecting sites within the Little Falls Dolostone formation.
Middleville, New York, USA
A well-known specific locality within Herkimer County, famous for producing high-quality Herkimer Diamonds.
Little Falls, New York, USA
Another significant locality in Herkimer County where these crystals are found.
Arizona, USA
Similar double-terminated quartz crystals, sometimes referred to as 'Arizona Herkimers', are found, though they are not true Herkimer Diamonds from New York.
Tibet
Double-terminated quartz crystals with similar characteristics have been found in Tibet, sometimes marketed as 'Tibetan Herkimers'.
Collecting tips
- Look for Dolostone Outcrops. Herkimer Diamonds are found in the Little Falls Dolostone. Search for exposures of this rock type, particularly in road cuts, quarries, and stream beds.
- Identify Vugs and Cavities. The crystals form in vugs. Look for openings, cracks, and pockets within the dolostone. These can range from small fissures to large caverns.
- Tools for Extraction. A rock hammer, chisels, and pry bars are often necessary to break open the dolostone and expose the vugs. Safety glasses are essential.
- Screening Material. Many crystals are found loose in the weathered soil and clay surrounding dolostone outcrops. Screening this material can yield numerous specimens.
- Hydrocarbon Inclusions. While not always present, the presence of black specks or oily residues can be an indicator of a potential Herkimer Diamond, as these are characteristic inclusions.
Quick Check
- Color:
- Colorless to transparent, sometimes with black or brownish hydrocarbon inclusions.
- Luster:
- Vitreous to sub-adamantine, very brilliant.
- Streak:
- White (as with all quartz varieties).
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