Crater of Diamonds State Park

Crater of Diamonds State Park is a unique geological preserve and public dig site located in Pike County, Arkansas, near the city of Murfreesboro, Arkansas. It is the only diamond-bearing site in the world open to the public, where visitors can search for and keep any gems or minerals they find. The park encompasses a 37.5-acre plowed field that is the eroded surface of a diamondiferous lamproite volcanic pipe. Managed by the Arkansas Department of Parks, Heritage and Tourism, it attracts tens of thousands of prospectors and tourists annually.

History

The site's geological significance was recognized in 1906 when John Huddleston, a local farmer, discovered the first diamonds on the property, sparking a series of commercial mining ventures. Early operations included the Arkansas Diamond Company and a short-lived attempt by Millard Fillmore's descendants. The most significant commercial effort was undertaken by the Mauney family and later the Houston and Texas Central Railroad-backed Arkansas Diamond Corporation. In 1952, the land was operated as a tourist attraction by private owners Howard A. Millar and his wife, leading to notable finds like the 15.33-carat "Star of Arkansas". The state of Arkansas purchased the property in 1972, creating the present-day park under the stewardship of the Arkansas State Parks system.

Geology

The diamond source is a volcanic pipe of olivine lamproite, which erupted through the surrounding Pennsylvanian-age sedimentary rocks of the Ouachita Mountains approximately 100 million years ago during the Cretaceous period. This igneous rock originated from deep within the Earth's mantle, carrying diamonds and other mantle-derived xenocrysts such as garnet, chromite, and ilmenite to the surface. The lamproite pipe is part of the larger Middle Cretaceous igneous province of central Arkansas. Over millions of years, erosion exposed the pipe and created a diamond-bearing elluvial deposit, which is the soil layer visitors search today.

Diamond mining

Unlike traditional kimberlite diamond mines, the park employs a "finders, keepers" policy for recreational surface collection. No heavy machinery or commercial extraction is permitted. Visitors primarily use simple tools like screens, shovels, and buckets to sift through the plowed soil, especially after rainfall when diamonds are easier to spot. The park staff provides identification services and mining tutorials. While diamonds are the premier find, the site is also prolific for over 40 other rocks and minerals, including amethyst, garnet, jasper, agate, and barite.

Notable finds

The park has yielded more than 33,000 diamonds since its discovery, including many large and famous gemstones. The largest diamond ever discovered in the United States, the 40.23-carat "Uncle Sam Diamond", was found here in 1924. Other significant finds include the 16.37-carat "Amarillo Starlight" discovered in 1975, the 8.52-carat "Esperanza Diamond" found in 2015, and the 6.19-carat "Limitless Diamond" unearthed in 2024. The "Strawn-Wagner Diamond", a 3.09-carat stone found in 1990, is renowned for being cut into a 1.09-carat gem awarded a perfect grade by the American Gem Society.

Park features and amenities

Beyond the search field, the park offers a modern visitor center with exhibits on geology and the site's history, including replicas of notable diamonds. The Diamond Discovery Center provides wet-sifting facilities and expert staff to help identify finds. Other amenities include a seasonal water park called "Diamond Springs", picnic areas, hiking trails, a campground, and a gift shop. The park frequently hosts events and educational programs related to gemology and the region's natural history.