Tourist finds a diamond the size of a piece of gum in a U.S. state park

A French visitor, Julien Navas, spent a January morning walking a plowed field in southwestern Arkansas and spotted a chocolate brown stone. Park staff later confirmed it as a 7.46 carat diamond, a rare find for any visitor.

He discovered it at Crater of Diamonds State Park, a public site where anyone can search a 37.5 acre field and keep what they find. The park recorded his gem and he named it after his fiancée.

Diamonds in an Arkansas park

Geologists such as J. Michael Howard at the Arkansas Geological Survey (AGS) have mapped the park’s volcanic feature.

They described how erosion keeps revealing fresh material, and also outlined the pipe’s layout and nearby rock types. That work helps explain why a careful surface search after rain can pay off.

The park sits on an eroded volcanic diatreme, a pipe that blasted deep rocks toward the surface during an ancient eruption.

The diamond bearing rock here is a type of lamproite, which can carry crystals formed under high pressure in Earth’s mantle.

Park crews plow the field at intervals so weather can wash lighter soil away and leave heavier gravel and gems on top, staff described the conditions that make big finds more likely. 

“We periodically plow the search area to loosen the diamond bearing soil and promote natural erosion,” explained Waymon Cox, Assistant Park Superintendent at Crater of Diamonds State Park.

“It is always so exciting to see first time visitors find diamonds, especially large diamonds like this one!” added Sarah Reap, Park Interpreter at Crater of Diamonds State Park. Excitement is part of the job for interpreters who see first time guests succeed. 

7.46 carat diamond find stands out

Carat measures mass, not size, so two diamonds of the same weight can look different if their shapes vary. A 7.46 carat stone is significant for a park that registers many small stones from casual searches.

Most guests who register diamonds report stones far under one carat, and the park reports that an average of one to two diamonds are found by visitors each day.

That steady pace encourages people to return and learn better techniques.

Crater of Diamonds allows visitors to keep any rock or mineral they find and identifies the three most common diamond colors on site as white, brown, and yellow.

The park’s website confirms those details and notes the 37 acre search field and on site identification help. Navas’ stone fits that color pattern while standing out for its size.

Brown coloration reflects how defects in the crystal lattice absorb light, which is normal for natural stones from many sources.

Color alone does not tell the full story, since clarity, shape, and how a cutter would fashion the gem also matter.

Short history of Arkansas diamonds

Arkansas has a long record of diamond finds at and around this field, including notable stones from public visitors and early miners.

The largest diamond ever found in the United States, the Uncle Sam diamond, was unearthed in 1924 near Murfreesboro and later cut to 12.42 carats.

Public access came decades later when the area became a state park and shifted from sporadic commercial attempts to visitor driven searching.

Since then, steady registration totals have made the site a staple of American geology tourism.

Today the park highlights notable finds and updates recent numbers, which keeps the public informed and motivated.

That transparency builds trust and supports simple, science based tips like searching after rains and scanning the ground for shiny, metallic luster.

The history also shows how science evolves as new mapping and sampling refine the story. Early reports used different rock names before later mapping favored lamproite for the diamond bearing units.

Arkansas Diamond Discovery Center

The field is open daily when weather allows, and guests can rent screens, shovels, and buckets next to the search area. Staff at the Diamond Discovery Center teach techniques and will identify finds at no charge.

Surface searching is the simplest method because diamonds are dense, often resist weathering, and can show a bright, oily sparkle in sunlight. Wet sifting lets water separate lighter dirt from gravel that may include a crystal.

Safety and preservation rules keep the area accessible to everyone. There are no battery powered tools, no pits, and no trenches, which protects both people and the exposed geology.

Families often plan visits after rainy periods when erosion has done some of the work for them. That strategy matches the way the field naturally concentrates heavy minerals in low spots.

Science notes for curious readers

Diamonds form deep in the mantle where high pressure and heat stabilize carbon in a crystal structure. Volcanic pipes carry those crystals up quickly, preserving them during transport to the surface.

Petrological study of the Prairie Creek diatreme has examined mineralogy and chemistry to better understand the source rocks and their evolution, providing a technical backdrop for what visitors see on the ground.

Those findings complement the state mapping and on site observations.

The park’s practice of plowing and letting rain expose heavier material lines up with basic geologic sorting. Heavy grains and durable crystals tend to stay put while fine silt and clay wash away.

Visitors who learn these basics often improve their search results through patient observation. Navas’ find shows how persistence and timing can matter in a field open to everyone.

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