Herkimer Diamond Mines

Useful Information

Location: 4601 State Route 28, Herkimer, NY 13350.
(43.128755, -74.976582)
Open: All year daily 9-17.
Closed during unsafe weather conditions such as: snow, sleet, harsh rains, thunderstorms.
Fee: Adults USD 16, Children (5-12) USD 13, Children (0-4) free.
Classification: MineFee Mining MineSchmucksteine
Light: n/a
Guided tours: self guided
Photography: allowed
Accessibility: no
Address: Herkimer Diamond Mines, Miners’ Village, Village Hall, Trading Post & Prospecting Area, 4601 State Route 28, Herkimer, NY 13350, Tel: +1-315-891-3099. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.



The Herkimer Diamonds are found in dolomite limestone. It was down lifted and under high pressure and temperature quartz rich water deposited the quartz very slowly in pockets or cavities. As the dolomite is rather easily dissolved by rain water which contains carbon dioxide, but quartz not, the small crystals are actually freed from the surrounding rocks by weathering. They can be easily found in the soil.


Herkimer Diamond Mines has, despite the name, nothing to do with diamonds. Actually this location is famous for beautiful double-terminated quartz crystals. This are crystals which do not grow from a surface, they grow in a sort of floating state. As a result they have a pointed end on both sides, instead of being fixed to the rock at the second end. This is quite rare and thus really special. And due to the colourless glass-like transparency and the well-defined crystal surfaces they actually resemble polished diamonds. Thus, they are called Herkimer Diamonds. The claim that they have "a diamond-like geometrical shape" on the other hand is nonsense, quartz is trigonal or hexagonal, diamond is cubic. And cut and polished diamond does not follow the geometric rules of natural crystals at all, but we have never heard of diamond which was cut into the same form as rock crystal.

The quartz crystal bearing dolomite reaches the surface near the town Middleville, New York. Weathering and erosion by glaciers has exposed the rock. The area is called Herkimer County, named after the Revolutionary War General Nicholas Herkimer. The crystals were simply named after their location.

This is not a show mine, it is a fee mine where you can collect quartz crystals in an open cast. For the mineral collecting you should wear appropriate clothes. Sturdy shoes, safety eye wear, gloves, and a hat are a good start. Bring equipment like chisels, screens, small shovels, buckets, and hammers. However, be very careful with steel hammers, they might break and the piece of steel will fly away with high speed and may hit and injure someone. Bring a geologist hammer if you have or at least a claw hammer or carpenter hammer, which is made of iron, not of steel. It makes hammering not only safer but also easier.