I’ve always been fascinated by peridot hunting in Iowa. While it’s not as famous as other gem locations, our state has some interesting spots where you can find these olive-green crystals.

Most folks don’t know this, but peridot can be found in several areas across Iowa. These gems aren’t just pretty – they’re actually pieces of ancient volcanic activity that happened here millions of years ago.

Before you grab your tools and head out, it’s worth knowing where to look. I’ve spent years exploring these locations, and I’m going to share some of the best spots I’ve found. Trust me, finding your first peridot is pretty exciting.

How Peridot Forms Here

Peridot forms deep within Earth’s mantle, around 20 to 55 miles below the surface, where intense heat and pressure create the perfect conditions. It’s actually made from magma that cools super slowly, letting the crystals grow nice and big.

The main ingredient is olivine, which needs temperatures between 1,000°C to 1,300°C to form properly. When volcanoes erupt, they sometimes bring these green gems up with them in basalt rocks.

What’s really cool is that peridot can also come from meteorites – yep, some of these crystals literally fell from space! The iron and magnesium inside the stone is what gives it that signature olive-green color.

Types of Peridot

Peridot’s value fluctuates based on its origin and quality, with its vivid colors making it a distinctive and sought-after gemstone. Here are the different types of Peridot:

Burmese Peridot

Burmese Peridot shows off a pure, bright green color that looks almost like spring leaves. Most other peridots have brown or yellow mixed in, but Burmese ones usually don’t.

The stone’s special green color comes from the iron inside the crystal. When light hits it, the stone seems to glow from within, creating a beautiful effect that catches everyone’s eye.

These stones often have special markings inside called “lily pads.” These are small, round patterns that look like tiny circles when you look at them with a magnifying glass.

You can often find Burmese Peridot in larger sizes, which makes them great for bigger jewelry pieces. The stones keep their bright color even under different kinds of lighting, so they look good both in sunlight and indoor light.

Pakistani Peridot

Pakistani Peridot is known for its vibrant green hues, which can range from yellow-green to olive green. The stones are usually very clear and shine beautifully when light hits them.

The stone typically has a vitreous luster and can be quite transparent, showcasing its brilliance. High-quality specimens can exhibit exceptional clarity with minimal inclusions, which enhances their appeal in jewelry.

Inside these stones, you might find tiny bubbles of liquid and gas. These create interesting patterns that make each stone has its unique pattern of these markings.

These peridots often come in larger sizes and maintain their bright color even under artificial light. This makes them look just as good in the evening as they do during the day, which is why some people call them “evening emeralds.”

Arizona Peridot

Arizona Peridot shows off a bright, lime-green color that sometimes has olive tones. The stones are usually smaller than other peridots but make up for it with their exceptional brightness and sparkle.

These stones often have a special kind of clarity that makes them appear very clean to the naked eye. When you look at them closely, you might see tiny specks of black minerals inside, which are typical of Arizona stones.

Arizona Peridot is especially famous due to its association with the San Carlos Apache Reservation, which is one of the largest sources of peridot in the world. The region’s peridot is highly valued not only locally but also within the broader gemstone market for its quality and vibrant color.

Changbai Peridot

Changbai Peridot displays a deep, rich green color that sets it apart. Their color is more intense than other peridots, showing deep forest green tones.

These stones usually come in medium sizes, around one carat. What makes them special is how clean they look – most have very few internal marks or inclusions. This clarity lets more light pass through, making them especially bright and sparkly.

The color of Changbai Peridot stays consistent throughout the stone. Unlike some other peridots that might show patches of different colors, these maintain their rich green tone evenly. This makes them particularly appealing when set in jewelry.

Their superior clarity and rich color have made them increasingly popular since 2005. Even though they’re newer to the market compared to other peridots, they’ve quickly gained recognition for their outstanding quality.

Vietnam Peridot

Vietnam Peridot, also known as chrysolite, has a special yellowish-green color that makes it easy to spot. They often come in larger sizes than peridots from other places.

When light passes through these stones, it creates a unique double-image effect. If you look closely at a faceted stone, you might see the edges appear doubled. This effect makes them sparkle in a special way.

Vietnamese peridot is often found in mafic and ultramafic rocks, which are rich in iron and magnesium, leading to the formation of larger and higher-quality stones.

The green color stays even throughout the whole stone. This consistent color is one reason why collectors really like Vietnam Peridot.

Norway Peridot

Norway Peridot comes in beautiful olive green shades. The color can range from light yellow-green to deep olive. The amount of iron inside the stone decides how dark or light the green will be.

When light enters these stones, it splits into two beams. This makes the stone look extra sparkly and bright, even when the light isn’t very strong. You can see this special effect best in well-cut stones.

Norway Peridot is part of a long tradition of peridot use in jewelry and artifacts, including significant pieces like those found in the Shrine of the Three Kings in Cologne Cathedral, which were initially thought to be emeralds but were later identified as large peridots.

Pallasite Peridot

Pallasite Peridot comes from space! These green crystals are found inside meteorites, mixed with metal from space. The green crystals stand out beautifully against the silvery-gray metal background.

These stones form a natural pattern in the meteorite. The mix of bright green crystals and shiny metal creates a beautiful design that looks like stained glass when light shines through it.

Scientists find these stones especially interesting because they tell us about how planets form. The mix of metal and crystal shows us what the inside of planets might look like.

These stones are pretty rare since they only come from meteorites. Collectors really like them because each piece tells a story about space and has its own unique pattern of green crystals.

Antarctica Peridot

Antarctica Peridot usually comes in smaller sizes, but each stone packs a lot of sparkle. They show a pure green color that can look slightly yellowish or olive in different lights.

These stones formed under extreme cold conditions, which affects how they look. They tend to be very clear with few internal markings. Most pieces are under two carats in size.

The extreme conditions where these stones formed make them special. They had to survive intense pressure and cold temperatures to reach the surface.

These stones are among the rarest peridots because they’re so hard to find. Their small size actually helps them sparkle more intensely than larger stones.

Hawaii Peridot

Hawaii Peridot has a rich olive-green color. Inside many stones, you can find special bubble-shaped marks called “lily pads.” These marks look like tiny round discs frozen in the stone.

One cool thing about these stones is that some of them contain tiny bits of gas trapped inside from when they formed. Scientists can study these bubbles to learn about conditions deep in the Earth.

In Hawaiian culture, peridot is associated with Pele, the goddess of fire and volcanoes, which adds to its allure among collectors interested in cultural artifacts.

New Mexico Peridot

New Mexico peridot typically ranges in color from brown and greenish-brown to yellowish-green and the more desirable green hue. This variety stands out due to its potential for a wider color range compared to peridot from other regions.

One notable aspect of New Mexico peridot is its occurrence in volcanic debris from ancient eruptions, specifically from a 180,000-year-old volcano. This geological background contributes to the unique properties of the stones found there.

The Kilbourne Hole area is particularly noted for producing high-quality peridot that is sometimes considered superior to that from Arizona.

What Rough Peridot Look Like?

Peridot has several distinctive characteristics that can help you identify it in its natural form. Here are the key features to look for:

Check for a glassy or waxy luster

Raw peridot typically shows a distinct glassy to waxy shine, even in its unpolished state. When you shine a light on it, you’ll notice it’s not quite as sparkly as quartz but definitely shinier than most common rocks.

Pro tip: if it looks kind of like olive oil frozen in stone form, you might be onto something!

Look for that signature olive-green color

Unlike other green stones, peridot has this unique yellowish-green to olive-green color that’s pretty consistent throughout the stone.

Here’s the thing – even when rough, it shouldn’t have dark spots or zones. If you spot patches of brown or black, you’re probably looking at something else.

Hold it up to natural light – a genuine peridot will show that characteristic color even in its rough form.

Examine the crystal structure

In its natural state, peridot forms stubby, prismatic crystals. Look for somewhat rectangular or barrel-shaped formations – they might be rough, but you should see hints of this shape.

Sometimes you’ll spot these crystals embedded in darker volcanic rock (that’s basalt, by the way). The surfaces might look a bit pitted or weathered, but they shouldn’t be perfectly smooth.

A Quick Request About Collecting

Tips on Where to Look

Peridot typically forms in volcanic areas and can be found in several accessible locations. Here’s where you should start looking:

Volcanic Rock Formations

Look for dark-colored basalt rocks and olivine-rich formations. Check areas where ancient lava flows have created large rock deposits, especially those with visible green crystals embedded in the rock. These rocks often weather over time, exposing the peridot crystals.

Stream Beds and Gravel Banks

Search in stream beds where water has naturally broken down volcanic rocks. Peridot is usually more concentrated in these areas because water carries away lighter materials while leaving behind heavier minerals.

This makes it easier to spot the olive-green crystals among the gravels and sands that have accumulated over time.

Old Mining Areas

Visit abandoned mine dumps and tailings, particularly those known for copper or nickel mining operations that were active in volcanic regions.

These areas often contain peridot as a secondary mineral, and since the rock has already been broken down during previous mining operations, the gems are easier to spot.

Some Great Places To Start

Here are some of the better places to start looking for peridot in Iowa:

The Mississippi River forms Iowa’s eastern border, stretching from Minnesota to the Gulf of Mexico. This river has shaped the land around it for thousands of years, creating rich soil deposits and varied landscapes perfect for rockhounding.

Over time, the movement of the river has created special spots called point bars where minerals and rocks collect. These areas form when the river bends, dropping sediments on the inner curve of each bend. These deposits contain various minerals, including peridot.

The best places to search for peridot are along the riverbanks after periods of high water when the river might expose new deposits.

Local rockhounds often check areas where streams feed into the main river, as these spots tend to collect minerals.

Keokuk Area

The Keokuk Area sits in Lee County, in southeast Iowa. This area is an amazing spot for rock collectors, mainly because of its famous Keokuk geodes. These round rocks might look plain on the outside, but crack them open and you’ll find stunning crystals inside.

The lower Warsaw Formation, a special layer of rock, is where most of the good stuff is found. While looking for peridot, you might also discover clear quartz crystals and white calcite.

The best places to search are along stream beds where water has cut through the rock layers. Creek banks and areas where streams meet are good spots to check.

Many collectors visit after heavy rains when new geodes and minerals get washed out. Local streams like Mud Creek and the Fox River valley are popular spots where rocks naturally collect.

Devonian Fossil Gorge

The Devonian Fossil Gorge is located next to Coralville Lake in Johnson County, Iowa. This special place formed after two big floods in 1993 and 2008 washed away layers of soil, showing off 375-million-year-old rock layers underneath.

You can spot old sea creatures like shells, snails, and coral that lived here when Iowa was under an ocean. The limestone rocks are full of these fossils, making this place popular with rock collectors and scientists.

The best areas to look for stones and fossils are near the entry plaza and along the marked walking paths. Pay special attention to spots where the limestone rock is visible at the surface. While looking for Peridot, you might also find other interesting rocks in the layers of exposed bedrock.

The gorge has clear walking paths and information signs that help visitors understand what they’re seeing. It’s like walking through pages of Earth’s history book, with each rock layer telling a different story about ancient Iowa.

Skunk River

The Skunk River flows for 93 miles through Iowa before joining the Mississippi River. In Henry County, the river cuts through ancient glacial deposits that are over 500,000 years old. These deposits make the area interesting for rock collectors.

The river area has rolling hills and deep valleys shaped by old glaciers. The riverbanks show different layers of rock from various time periods, including Mississippian and Devonian formations. This mix of rock types means you might find different kinds of minerals here.

The best spots to look for Peridot and other stones are along the riverbanks, especially where the North and South Skunk Rivers meet. Focus on areas where water has worn away the soil and exposed the bedrock underneath.

The Skunk River area is part of the Southern Iowan Drift Plain, which is known for its thick layers of glacial till and loess (wind-blown soil). These features have created good conditions for finding various rocks and minerals over time.

Places Peridot has been found by County

After discussing our top picks, we wanted to discuss the other places on our list. Below is a list of the additional locations where we have succeeded, along with a breakdown of each place by county.