Here’s a family vacation you probably never tried: Mining for diamonds. In the US. It’s in Herkimer NY, in Upstate New York. Technically, you’ll be mining for double-terminated (two pointy ends) quartz crystals with multi-faceted sides. But who wants to get technical? The Herkimer Diamond Mine has been the go-to spot for visitors who wanted to mine for quartz crystals since the 1950s. But in recent years, it has become a family destination.

Herkimer NY Diamonds

The double-terminated (two pointy ends) quartz crystals with multi-faceted sides you'll find at the Herkimer Diamond Mine

Photo: Angela Tiffin, History Buff Traveling Mom

Herkimer diamonds measure 7.5 on what is known in the gem world as the Mohs hardness scale. Their more expensive cousin weighs in at 10. In some ways Herkimer diamonds are more interesting because they form free-floating in pockets of clay. When you find them, they are already shining and cut like you would expect a diamond to be.TMOM Travel Disclosure

These gemstones are believed to be about 5 million years old. It is believed that during the late Cambrian period the lower Adirondack plain and foothills of the mountain range were steadily being covered by layers of clean beach sand and carbonates. About 25 million years later, these limey deposits were covered over by thousands of feet of sedimentary deposits and compacted to form layers of limestone rock. One of these layers is called dolomite and it is inside this rock that Herkimer Diamonds can be found.

History of Herkimer Diamonds

Photo: Angela Tiffin, History Buff Traveling Mom

Photo: Angela Tiffin, History Buff Traveling Mom

There is much lore about who originally discovered crystals in the area. The most popular speculates that two Revolutionary War soldiers happened upon some quartz crystals laying loose in the soil and thought they were diamonds. Their commanding officer, the famous General Herkimer, learned of their find and planned on financing the war with the diamonds, only to learn later that they were not the real thing.

Prospecting for Herkimer Diamonds

With the price of admission, visitors over 5 are given a 5-pound sledge hammer and little plastic zip bags. Protective glasses are recommended and can be bought at the center or you can bring a pair from home.


Frequent visitors have various techniques for finding the diamonds and are happy to share with newcomers. You can find some smaller crystals just by scanning the ground but you’ll need to break off pieces of rock and look underneath for the bigger finds. A small chisel would be helpful to break the rocks apart.

One of the fun aspects for kids is the chance to take a hammer and smash away. For parents it is a bit nerve wracking at first watching kids waving around hammers. But once the first diamond is discovered, the kids focus more on finding another then chasing their sibling around with a hammer.

Some families love it so much that they rent one of the small cabins on the property and stay the night so they can prospect again in the morning.

Be forewarned: Similar to prospecting for gold, this activity can be addicting and you’ll find yourself saying, “We’ll go home after we find one more.”

Diamond Activity Center

Examining the treasure at Herkimer NY Diamond Mines

Photo: Angela Tiffin, History Buff Traveling Mom

The center is just as much fun for kids as the prospecting because it has unusual rocks, fossils and gemstones from all over the world to peruse and purchase. For moms, it has a large selection of beautiful crystal jewelry (also sold on the Home Shopping Network). For about $14, kids can design their own rings and necklaces with the diamonds that they found and the staff will prepare them.

There is a small museum upstairs with video presentations that talk about the origins of various gemstones and fossils.

For kids who do not make many finds or if you don’t have time to visit the quarry, have no fear, the center also sells bags of fossils and gems for sluicing. To sluice, (say it three times fast) you empty the bag of sand, a little at a time, into a sieve over a water trough and dip it in the water and watch what treasures come to the surface. Bags filled with sand, fossils and gemstones from all over the world can be purchased for $11 each.

Herkimer NY Diamond Mines

Fossil finds from a sluicing bag – photo: Angela Tiffin, History Buff Traveling Mom

What to Bring

  • Safety goggles or cheap sunglasses
  • Sunscreen and hat – there is not a lot of shade
  • A small chisel wouldn’t hurt

Dining Options

Adjacent to the activity center is the Rock N’ Roll Café, which serves basic family-friendly options like chicken strips, burgers and ice cream sundaes. It is open every day from 10:30am-4:30pm. Further down the road is the Crystal Chandelier, which has more dinner options but is still family-friendly and includes a children’s menu with real food like ribs and, spaghetti and meatballs.

Admission and Hours

The quarries and the shop are open from April until October from 9am-5pm (6pm during the summer months). In summer, 2015, admission is $11 for ages 13+ and $9 for age 5-12, kids under 4 are free.