Ace of Diamonds Mine & Campground

Middleville, New York
🌍 Land Type: Fee Dig (Private)
💰 Fee: Fee dig site (CLOSED for 2026 season)
Approximate — check official site before visiting
📅 Season: Closed for 2026 season
📊 Difficulty: easy

Family-owned Herkimer diamond mine and campground operating for over 50 years. Visitors could mine for Herkimer diamonds, garnets, and calcite. Currently closed for the 2026 season due to ongoing litigation among landowners. Online shop remains open. May reopen in the future.

Herkimer Diamond Quartz Garnets Calcite 🪨 Rockhounding

🪨 What You Can Find Here

Herkimer Diamond Quartz

Also found at:

Garnets

Deep red almandine garnets are found in many states. Idaho's star garnets are among the rarest in the world.

Also found at:

Calcite

Common but versatile carbonate mineral that forms in many crystal habits. Found in geodes, cave deposits, and veins throughout the US.

Also found at:

📍 Nearby Locations in New York

Benson Mines

St. Lawrence County, New York · Fee Dig

Historic mining area in the Adirondacks producing garnet crystals and iron minerals. Garnet mining was once a major industry here.

GarnetsHematiteMagnetite

Crystal Grove Diamond Mine

St. Johnsville, New York · Fee Dig

Hunt for the famous Herkimer diamonds — beautiful double-terminated quartz crystals first discovered in New York. Equipment rental available.

Quartz Crystals

Gore Mountain

North River, New York · Fee Dig

World-famous for giant almandine garnet crystals, some exceeding 2 feet in diameter. Home of the world's largest garnet deposit.

Garnets

Herkimer Diamond Mines

Middleville, New York · Fee Dig

The original Herkimer diamond mining experience. Multiple sites in the area allow digging for these perfectly clear double-terminated quartz crystals.

Quartz Crystals

LCT Lithium Mine

Benson Mines Area, New York · Fee Dig

Pegmatite deposit producing beryl, garnet, and quartz crystals in the Adirondack region.

BerylGarnetsQuartz Crystals

Rose Hill Mine

Ogdensburg, New York · Fee Dig

Famous mineral locality in the Balmat-Edwards district known for fluorite, sphalerite, and calcite specimens.

FluoriteSphaleriteCalcite

⛏️ Recommended Gear

Make the most of your visit to Ace of Diamonds Mine & Campground with the right equipment.

Rock Hammer

The most essential rockhounding tool. Choose a hammer with both a flat striking face and a pointed pick end.

Typical: $25-45

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Safety Glasses

Mandatory protective gear. Rock chips fly unpredictably when hammering.

Typical: $10-20

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Chisel Set

Cold chisels in 3-4 sizes for precise extraction from matrix rock.

Typical: $15-30

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Geologist's Pick

A heavier crack hammer for splitting hard rock. Essential for hard rock mining areas.

Typical: $35-60

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Sifting Screen

Stackable mesh screens for sifting gravel and dirt. Essential for gem and fossil hunting.

Typical: $20-40

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UV Flashlight

Long-wave UV light for finding fluorescent minerals and Yooperlites.

Typical: $15-35

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