Ace of Diamonds Mine & Campground – Middleville, NY


Ace of Diamonds Mine and Campgrounds

Disclosure: I was not compensated for this review.

Our family likes to check out a variety of family-friendly activities, and so last year we checked out the Ace of Diamonds Mine & Campground in Upstate New York, where you can look for Herkimer diamonds.

So what are Herkimer Diamonds?  These are “brilliant, water clear quartz crystals composed of silicon dioxide, hard enough to scratch glass”.

Dolomite limestone is the rock formation in which they are found. This rock was buried ages ago. Subsequently, surface water containing silicon seeped downward through the earth and was trapped in pockets or cavities in the dolomite rock. Under tremendous heat and pressure these crystals were formed. Weathering and erosion by glaciers and water have exposed the strata in Middleville, New York. the crystals are found mostly in rock cavities (formed approximately four hundred million years ago) but many are found in soil surrounding the weathered rocks.

The name Herkimer Diamond came about because to the untrained eye the sparkling crystals look like real diamonds and since these unique crystals are found in Herkimer County, named after the Revolutionary War General Nicholas Herkimer thus the name Herkimer Diamonds. Additionally, the Mohawk Indians, native to this area, are known as “The People of the Crystals”. (

This part mine, part campground, is located in Middleville, NY, which is approximately 1 hour and 45 minutes from Albany, NY.  Ace of Diamonds is located right on NYS Route 28, and we went right by it before realizing we needed to turn around.  Their website describes the mine as “A road cut in the dolomite rock exposing a rock ledge readily identifies our place.”

Once we parked, we headed into the gift shop to purchase our tickets.  The gift shop also has trinkets, gems, and snacks for sale, and there are bathrooms next to the shop (a must for kids and for washing up!).

The mine is a large, open area.  It begins right at the parking lot, so you don’t need to drive or hike to the mine.

Ace of Diamonds

We brought our own supplies.  If you can bring your own, I recommend bringing:

– eye protection and/or sunglasses
– sunscreen, hats
– pants
– knee pads or a kneeling pad (like the kind you might use for gardening)
– small collection containers
– change of clothes
– water, food

The gift shop does rent some supplies, but you may want to consider bringing your own sledgehammer, rock hammer, goggles, buckets, or gloves.  Obviously these are tools that adults only should be using, and away from kids (so you don’t have pieces chipping and flying off).

Since the mine goes right up to the parking lot, you can keep supplies in the car (such as a change of clothes, water cooler, lunch, etc).

Ace of Diamonds Mine

The kids had fun rooting around in the rocks for gems, and getting really dirty too!  Be sure to dress the kids in clothes they can get dirty, but also clothes are are ok with the possibility of getting a little ripped up too (from moving around on the rocks).  You may want to have them wear pants because you want to be careful about those little knees getting scraped up.

Ace of Diamonds Mine

We watched the kids carefully (who were 3 and 6 at the time), to make sure no one fell or got hurt on the rocks.  The footing can be unsteady and I certainly didn’t want the kids tripping and falling.

Ace of Diamonds Mine

By the time we left, we had collected a small jar of Herkimer Diamonds.  The kids collected a number of Herkimer Diamonds by sifting through the rocks without any help, and my husband was able to find some by breaking open rocks.  We found some pretty good-sized gems just by looking through rocks, which was exciting for the kids.

Ace of Diamonds Mine

Our largest Herkimer Diamond from the trip.

Ace of Diamonds Mine

Ace of Diamonds Mine

Overall, this was a fun and interesting day trip, and certainly a unique experience.  The kids ended up taking their ‘diamonds’ to school for show and tell!

The mine is open from 9am-5pm, April 1st to October 31st (call ahead to confirm).


Visit the Ace of Diamonds website at


Disclosure: I was not compensated for this review.



  1. 1
    Julie Wood says:

    Wow! What a fun activity to do with the kids and have them dig for diamonds. The diamonds are very pretty and the Campground is great to go on vacation.

  2. 2
    Kimberly Flickinger says:

    I never been there, but it looks like something I need to put on my bucket list. Looks like a lot of fun!

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