North Country gold: How and where to find Lake Superior agates

Timing can be everything when it comes to finding Lake Superior agates.

"It's like treasure hunting," says Butch Goldenstein of St. Cloud, an agate enthusiast who manned a table at the annual Agate Days celebration in Moose Lake earlier this summer. "There's a thrill in finding them. And there's nothing like walking in somebody's footsteps and saying, 'Oh, you missed this one.' "

Agate pickers live for those moments when they find these beautiful banded rocks, allowing them to connect with the region's geology.

What makes Lake Superior agates so special? Formed in and around the lake during volcanic eruptions about a billion years ago, these gemstones were distributed across the landscapes of northeast Minnesota and northwest Wisconsin during a later bout of glacial activity, roughly 10,000 to 15,000 years ago. They come in a variety of shapes, sizes and colors, often with beautiful banding, luminescence and other features. Simply put, agates stand out from the plainer rocks that often hide them.

So they are treasured. Agates have been Minnesota's official state gemstone since 1969.

While they can be purchased at rock and gem shops throughout the Upper Midwest, it's so much more fun and rewarding to find them on your own. As an added bonus, agate-hunting makes for a great family activity.

Here are some tips on making your next excursion a success, whether it's your first or your 50th time looking for agates:

KNOW THE LOOK

Understand that there is broad variety in agates, so it's helpful to know the range of characteristics.

"I think you develop an eye for agates," says Goldenstein, who has picked agates for more than 60 years. "That comes from picking up thousands of stones. Some are and some aren't."

One of the best clues is a waxy, almost glossy surface. Many agates are translucent, but some are more opaque.

Agates come in a range of colors, and iron oxide staining is found on most agates, with the most common shades being rust-red and yellow.

The agate's famous bands aren't always visible. Sometimes the bands face down in the dirt. Sometimes the rocks bear less orthodox patterns, without the classic cross sections. Other times the bands have broken away, leaving them partly peeled off, almost like banana skin.

Agates are generally round, since they were formed in bubble holes in lava. Look for pitting or dimples on the outer surface.

KNOW WHERE TO LOOK

The most obvious place to find agates — Lake Superior — is actually the least favorite of most expert rockhounds.

"I've hunted on the beaches many times, but so have 3 billion people from around the world," Goldenstein says.

It can be difficult to find agates on Lake Superior, but it's not impossible. And it's hard to beat that view of the lake.

Right after a big storm is a good time to look, as wave action can reveal more agates. But it's also helpful to go on a calm, sunny day, which is best for spotting translucent nuggets in the water.

Hard-core agate pickers love to look in gravel pits, but it's gotten increasingly difficult to get permission to enter them. Owners are concerned about liability, and a working pit can be a dangerous place.

Don't trespass. Property owners are a lot more likely to let pickers into pits that are no longer in operation.

Longtime agate picker Allen Hyopponnen of Duluth is among those who won't waste his time anywhere but a gravel pit.

"It's pretty much a dead end" if you don't have access to one, Hyopponnen says, noting that county-owned pits generally let in rockhounds.

But there are other options.

Glaciers deposited these gems across the countryside, sprinkling them into the region's many lakes and streams — from rivers flowing into Lake Superior to shallow, rocky creek beds throughout the region. Don't overlook these spots, especially if you can find an area with a lot of rock — a rocky shoreline, a washed-out cliff with a lot of stone or perhaps a washout along the roadside.

Agates can often be found on rural gravel roads, since many were laid with rock from the region.

But one of the best places to look is agricultural fields, especially those with rolling hills. Farmers generally grant permission to walk their fields. Just ask.

Try scouting for rocky deposits in those fields early in the growing season, before crops have even been planted.

For that matter, any time you find lots of rock, whether on the beach, a cornfield or elsewhere, it's worth a closer look.

The first thing Goldenstein does is look at the makeup of the rock.

If it's mostly granite or limestone, he won't waste any more time there.

But if he finds a lot of basalt, which agates were formed inside of, or quartz minerals, which agates are made of, he gives the location his undivided attention.

A lot of the time, it comes down to luck and timing.

Goldenstein mentions the time a women showed him an amazing 2-pounder at a rock and gem show.

"I asked her how long she's been picking to find a rock like that, and she said, 'Oh, I'm not a picker. I found this in my back yard doing some work.' It was her first agate. So there's crazy things out there."

Javier Serna is a freelance outdoors writer based in St. Paul. A lover of woods and waters, he often has a hard time deciding whether to fish or hunt agates.