From the Mississippi River to Lake Michigan, from the shores of Lake Superior to the Illinois border, Wisconsin’s diverse landscape holds hidden treasures.

In this article, we’ve scoured the state to bring you the 9 best places to find diamonds in Wisconsin.

Save time and energy by focusing your search on these top locations, carefully selected to maximize your chances of discovering these precious gems.

Get ready for an exciting adventure as we guide you through the most promising diamond-rich areas in the Badger State.

How Diamond Forms Here

Diamonds form deep within the Earth, about 90 to 200 kilometers below the surface, where conditions are extreme.

Here, carbon atoms are subjected to intense heat—around 900 to 1,300 degrees Celsius—and immense pressure, about 45 to 60 kilobars. This environment causes the carbon to crystallize into diamond structures over millions to billions of years.

Over time, erosion and weathering expose these stones, making them accessible for mining.

What’s amazing is that each diamond’s journey from deep within the Earth makes it unique, with its own shape, size, and clarity.

The Types of Diamond

Diamonds are classified into various types based on their structure and color. Here are some of the popular types of diamond:

Black Diamond

Black diamonds, also known as carbonados, are truly one-of-a-kind. Unlike their clear cousins, these stones are opaque and have a matte finish.

They don’t sparkle in the traditional sense but have a unique, mysterious charm all their own.

What makes black diamonds special is their age and formation. Most are believed to be 2.6 to 3.2 billion years old, making them some of the oldest gemstones on Earth.

Their dark color comes from numerous inclusions and the presence of graphite or other minerals.

Recently, a massive black diamond called “The Enigma” made headlines. Weighing 555.55 carats, it showcases the growing interest in these unusual stones.

Yellow Diamond

Yellow diamonds shine with a vibrant, sunny hue. Their color ranges from light yellow to deep, intense shades.

This beautiful color comes from nitrogen atoms in the diamond’s structure. These atoms absorb blue light and reflect yellow, giving the stone its unique appearance.

Unlike clear diamonds, yellow diamonds are graded based on their color intensity. The deeper and richer the yellow, the more valuable the stone. This grading system is different from the one used for colorless diamonds.

Blue Diamond

The color of the blue diamond can range from a soft, icy blue to a deep, vivid shade. This striking blue comes from boron in the diamond’s crystal structure. It’s a rare occurrence in nature, making these diamonds very uncommon.

One cool thing about blue diamonds is how they react to ultraviolet light. Many of them show a unique glow called fluorescence. This can make their color even more impressive under certain lighting.

Blue diamonds have some famous examples. The Hope Diamond is probably the most well-known. It’s known for being the largest diamond weighing 45.52 carats. It’s current value is estimated to be US$200–350 million.

Red Diamond

Red diamonds are incredibly rare and highly prized. Their distinct red color comes from structural imperfections in the diamond’s crystal lattice, not from chemical impurities like other colored diamonds.

These diamonds are so rare that very few have ever been found. Each discovery of a red diamond is a significant event in the gemstone world.

Their rarity makes them even more valuable than pink or blue diamonds, which are already considered extremely precious.

Some famous red diamonds have captured public attention. The Moussaieff Red from Brazil and the Kazanjian Red Diamond from South Africa are notable examples.

In 1987, a red diamond (Hancock Diamond) sold at auction for a record-setting $927,000, highlighting the extraordinary value placed on these rare gems.

Pink Diamond

Pink diamond’s color can be a soft, delicate pink or a deep, vivid rose. What’s interesting is that scientists aren’t entirely sure why they’re pink. It’s thought to be due to a twist in their crystal structure, not because of any specific element.

These diamonds are incredibly scarce. For every million carats of rough diamonds mined, only one carat might be a pink diamond. This rarity makes them highly prized by collectors and jewelers.

Even small pink diamonds can be worth a lot because of their rarity. They’re often used in high-end jewelry, where their unique color makes a big impact.

Green Diamond

Green diamonds are some of the most unusual and unique colored diamonds. Their color can range from a light mint to a deep forest green

What makes them special is how they get their color. It’s not from a chemical element, but from exposure to natural radiation over millions of years.

This natural coloring process is incredible. It happens when diamonds are near radioactive rocks deep in the earth. The radiation changes the diamond’s crystal structure, creating the green color.

Green diamonds often show unique light effects. Some might have a strong glow under certain lights, adding to their allure.

What Rough Diamonds Look Like

Rough diamonds can be challenging to identify. Here are a few proven techniques that will make it easier for you to identify the rough diamond:

Check for a Glassy or Waxy Luster

One of the most noticeable features of a rough diamond is its luster. Uncut diamonds often have a glassy or waxy appearance.

This is because the rough surface scatters light differently than a smooth, cut surface.

Look for an Octahedral Shape

Rough diamonds typically take on an octahedral shape, which resembles two pyramids joined at the base. This shape is a result of the diamond’s cubic crystal structure.

However, not all rough diamonds will have a perfect octahedral form, as they can be distorted or irregular due to natural forces during formation.

Assess the Density and Weight

Diamonds are known for their density and weight. A rough diamond will feel heavy for its size compared to other stones.

You can test this by holding the stone in your hand and comparing it to a known non-diamond.

Look for a Crystalline Texture

When examining a rough diamond, you may notice a distinct crystalline texture on its surface.

This is due to the diamond’s atomic structure and can help distinguish it from other minerals or synthetic stones.

A Quick Request About Collecting

Tips on where to look

Once you get to the places we have listed below there are some things you should keep in mind when you’re searching:

Look in Sedimentary Rocks

Sedimentary rocks are a great place to start. These rocks form from layers of materials that have settled over time.

Diamonds can be found in these layers. Look for areas where the rock has been worn down or eroded. This is where diamonds might be exposed.

Explore Riverbeds

Rivers are another excellent spot. Over time, water carries diamonds downstream. Look for gravel beds in rivers. These spots can hold diamonds that have been washed away from their original location.

Pay attention to bends in the river. These areas often collect heavier materials, including diamonds.

Check Old Mining Sites

Old mining sites are worth exploring. Many diamonds were left behind during past mining activities.

Look for areas where mining was done in the past. Even if the site is no longer active, it can still be a good place to find hidden gems.

Investigate Hillsides

Hillsides can also be promising. Erosion can expose diamond-bearing rocks. Look for loose soil or rock on slopes.

These areas may reveal diamonds that have been pushed to the surface over time.

Some Great Places To Start

Here are some of the top locations in Wisconsin where you can begin your search for diamonds. These sites are among the best in the state for diamond hunting:

Kohlsville

Kohlsville, located in east-central Wisconsin, is a great spot for finding diamonds. This area is known for its glacial history, which has created perfect conditions for diamond deposits.

The famous “Theresa” diamond (the largest Wisconsin diamond), weighing 21.25 carats, was found here, making it a must-visit for gem hunters.

To search for diamonds, start at the Kohlsville River. Look along the riverbanks and in the gravel bars, especially where the water flows slowly. These spots can collect stones washed down from upstream.

Don’t forget to check the Kohlsville Millpond. The shores can reveal hidden treasures, especially after water levels drop. You can also explore nearby fields and wooded areas, as recent soil disturbances can uncover buried gems.

Mississippi River

The Mississippi River in La Crosse County flows through the southwestern part of the state, offering a stunning natural landscape. This area is known for its rich geological features, including high bluffs that line the riverbanks.

These bluffs are significant for gemstone hunters, as diamonds can sometimes be found in the gravels and sediments washed down from the hills. The river itself is a vital waterway, providing diverse habitats and a unique ecosystem.

Gem enthusiasts often explore the creeks and gravel bars along the Mississippi, where natural erosion has exposed various minerals.

The combination of the river’s movement and the geological history of the area makes it a promising spot for finding diamonds.

Rock Elm

Rock Elm, located in the southwestern part of Pierce County is situated about 25 miles southwest of Menomonie.

This quaint town has a rich history of diamond discoveries, with reports of 13 diamonds found during gold panning between 1881 and 1888.

The area is geologically fascinating due to the Rock Elm Disturbance, a meteorite impact crater approximately 6 kilometers in diameter. This unique geological feature, dating back to the Middle Ordovician period, offers a distinctive landscape for rockhounding.

To find diamonds, explore the gravels and creek beds around Plum Creek, where erosion and natural sorting can reveal these precious stones.

Oregon Area

The Oregon Area in Dane County is located in the southern part of the county, just south of Madison. In 1893, a diamond was discovered here, making it a notable site for gem hunters.

The area’s glacial deposits, including till and outwash plains, provide an excellent opportunity to uncover unique specimens.

Gravel pits, creeks, and streams are prime spots to search, as they often contain a mix of materials brought in by glacial activity. Construction sites can also yield surprising finds, as digging and excavation can reveal buried rocks and minerals.

Port Washington

Located in the southeastern part of Wisconsin, the Port Washington area is just a mile west of the stunning Lake Michigan.

This coastal region is characterized by its impressive bluffs and beautiful natural preserves, making it a scenic spot for outdoor enthusiasts.

Historically, this area is noteworthy for the discovery of a diamond in 1881, highlighting its potential for gemstone hunting.

The unique geological features of the Lion’s Den Gorge Nature Preserve, with its towering 90- to 100-foot bluffs, create an ideal environment for rockhounding. Here, you can explore the shoreline and gravels where various stones are often uncovered.

The combination of erosion and natural processes along the lakefront enhances the chances of finding not just diamonds but also other intriguing minerals. 

Places Diamond has been found by county

Following our discussion of the top selections, we would like to highlight the other locations on our list. Below is a compilation of the additional sites where we have achieved success, along with a detailed breakdown of each location by county.