Collecting Calcite Clams in Florida

Florida is a treasure trove for fossil hunters, particularly those seeking calcite fossilized clams. These unique specimens, formed when calcite crystals replace the original clam shells millions of years ago, are prized for their beauty and scientific significance.

Calcite Fossilized Clams Collecting in The Fort Drum Mine, also known as the Rucks Pit or Fort Drum Crystal Mine

Calcite crystals represent the most commonly-collected mineral from Florida. As most of Florida is underlain by Tertiary to recent marine limestones, the potential for crystal finds exists just about anywhere these limestones are exposed – most prominently in active limerock quarries. 

The premier location for finding these calcite-filled clams in Florida is Ruck's Pit near Fort Drum. This family-owned property allows visitors to dig for a fee and offers a high chance of finding these unique treasures.

The gem-like crystals were discovered after the hard limestone deposits came to be excavated for aggregate.

Nowadays another location 2 blocks west have been opened. Ruck's Pit in Fort Drum, Florida, which is owned and operated by Eddie Rucks, is the PRIME locality to find minerals and fossils combined in the same specimen. Specimens from this locality range from 1.6 to 2 million years old.

What to Expect at Rucks Pit

Loose, gem-quality calcite crystals and crystal clusters. Some individual crystals can be over an inch long. Large, fossilized clams filled with calcite crystal

Other fossilized shellfish, like whelks and olive shells. On rare occasions, you’ll find one of these filled with tiny crystals.

You may also find other fossils, such as sharks' teeth and prehistoric animal bones.

The pit also has a variety of minerals, including quartz, pyrite, and hematite.

Ruck's Pit Calcite Clam. Photo: Rockhounding Florida

Tips for happy hunting

• Visit during the dry season: The dry season (typically between November and April) offers better conditions for digging and uncovering your finds.
• Wear comfortable clothes that you won’t mind getting dirty. Because they will.
• Boots – or other shoes with ankle support – are a good idea. Loose rocks can give you a twist.
• Wear gloves. The tiny, fossilized shells that make up the rock can have rough edges.
• Bring a hammer, chisel, hoe and flathead screwdriver. The driver is a valuable tool for carefully loosening the dirt and rock around your fragile finds.
• Bring newspapers. Calcite is “soft” crystal and easily scratched. Wrap your finds before they go in your bucket.
• Bring a cooler and plenty to drink.
• Wear sunscreen. While there are shade pavilions, when you get the “crystal fever,” you’ll forget how long you’ve been standing in the sun.

When you are digging in the right area, you will find whole beds of clams like these two. Photo: Mineral Movies

Ruck’s Pit is in the midst of a transformation and will eventually become a full-service campground. There’s already a swimming beach at the lake, so if you get too hot, you can take a dip. The lake is also stocked with bass, bluegill, catfish and tilapia for catch-and-release fishing.