arkansas volcano crater diamonds state park

Ancient Volcano in Arkansas: Crater of Diamonds State Park

Arkansas does not have any active volcanoes but you can dig for diamonds in the crater of an ancient volcano located in southwest Arkansas.

If you aren’t from Arkansas, you may not have known that we hold the title of having the only public diamond mine in the world. You can actually come here and dig for diamonds with your own shovel (or you can rent if you didn’t bring your own).

If you find a diamond, you can keep it. Finders keepers. Losers weepers.

Crater of Diamonds State Park sits on top of an ancient volcanic pipe.
Crater of Diamonds State Park sits on top of an ancient volcanic pipe. Photo credit: J. Michael Raby/Flickr

It’s that easy. In September 25, 2020, an Arkansas man discovered a 9.07-carat diamond at Crater of Diamonds State Park on Labor Day. It was the second-largest diamond found in the 48-year history of the State Park.

“246 diamonds have been registered at Crater of Diamonds State Park [in 2020], weighing a total of 59.25 carats. On average, people find one or two diamonds there daily.” -source

Flowed field ready for digging on top of Arkansas' own ancient volcano.
Plowed field ready for digging on top of Arkansas’ own ancient volcano. Photo credit: ZhaoScorpio/Flickr

Digging for diamonds is a lot of fun but how many people have actually stopped to wonder why this area is called Crater of Diamonds State Park? What makes it a crater?

Crater of Diamonds State Park actually sits on top of an ancient volcano!

“One of the only places in the world where the public can search for real diamonds in their original volcanic source, Crater of Diamonds is a one-of-a-kind experience that brings people from all over the world to Murfreesboro, Arkansas. Visitors to the park search a 37-acre field, the eroded surface of a volcanic crater, for a variety of rocks, minerals, and gemstones – and any rock or mineral you find is yours to keep.” -source

The Uncle Sam Diamond is the largest diamond ever discovered in the United States.
The Uncle Sam Diamond is the largest diamond ever discovered in the United States. Photo credit: Erin/Flicker

According to Wikipedia, “The Crater of Diamonds volcanic pipe is part of a 95-million-year-old eroded volcano. The deeply sourced lamproite magma, from the upper mantle, brought the diamonds to the surface. The diamonds had crystallized in the cratonic root of the continent long before and were sampled by the magma as it rose to the surface.” -source

Let’s get technical for a minute:
Scientists say that the origins of Arkansas diamonds are unusual. Almost all diamonds in the world are mined from kimberlite and from alluvial deposits of diamonds that are weathered from kimberlite. However, Arkansas diamonds are mined from lamproite.

digging for diamonds in Arkansas volcano
Could there be a diamond in there? Photo credit: ZhaoScorpio/Flickr

Kimberlite is an igneous rock that can sometimes contain diamonds. Kimberlite is named after Kimberley in South Africa where an 83.5-carat diamond was discovered around the year 1869.

Lamproite is an “ultrapotassic mantle-derived volcanic or subvolcanic rock.” -source

Lamproite is formed from partially melted mantle deep within the Earth and then that molten material is forced to Earth’s surface in volcanic pipes. As the material moves up, it brings diamonds from the mantle regions where diamonds are formed.

So, when you dig for diamonds at Crater of Diamonds State Park in Arkansas, you are actually digging in the eroded surface of the volcanic pipe which brought those diamonds to the surface many, many years ago.

Old mine shack at Crater of Diamonds State Park AR
Old mine shack at Crater of Diamonds State Park. Photo credit: J. Michael Raby/Flickr

“Due in part to the park, and also because Arkansas was the first place outside South Africa where diamonds were found at their original volcanic source, this special gem has come to be associated with the Natural State. A large diamond symbol has dominated the state flag since 1912. The Arkansas State Quarter, released in 2003, bears a diamond on its face as do the current license plates.” -source

Arkansas has a lot to offer! Check this out: Things you can ONLY get in Arkansas.

You’ll also like this: Mauney’s House: Diamond-Sized Secrets

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