Herkimer Diamond Mines
Break open dolostone in the open surface mines with a hammer to free doubly terminated quartz crystals, or screen a purchased bag at the sluice station.
The visit
Why it is worth the trip
Cracking rock to reveal a fully formed crystal makes the link between host rock and finished gem material immediate rather than theoretical.
Before you go
The site states that everything you find is yours to keep, that no reservations are needed, and that admission includes an all-day prospecting ticket, collection bags and use of a rock hammer. Closed-toe shoes are required, eye protection is recommended, children aged 4 and under are not given tools, and tools over 12 lbs and powered equipment are not allowed.
Compiled from herkimerdiamond.com, read on August 16, 2026.
Opening times, seasons and prices change, and we are not the operator. Confirm directly with the venue before travelling. We take no commission on any visit.