A quest for the elusive Lake Superior agate

Lake Superior agates are part of the Minnesota vacation experience. We see the polished rocks and locally made jewelry in tourist areas, but have you ever actually found one?

Duluth and Lake Superior have always been favorite destinations of mine. For several years I was part of an annual summer weekend girls trip to Duluth. We’d stay in Canal Park, shop and hit a cultural attraction or two.

One summer, Roz and I decided to split off from the group to look for agates. With my copy of “Rock Picker’s Guide to Lake Superior’s North Shore” we headed out early.

The 36-page, beautifully illustrated guide said Kitchi Gammi Park was a decent agate beach. We pulled over. The lake was shimmering and the breeze delightful. With the classic hunched-over look of beachcombers, we walked up and down on a beach of smooth basalt and rhyolite rocks for a couple hours.

Finally, I spotted a translucent red rock. Lake Superior agates come in all sizes, and I had several nice specimens back home. Unfortunately, this one was only about a quarter inch around. Roz had no better luck. We sadly headed back for the designated group lunch.

TOURIST Lake Superior Agates

Meanwhile, back in Canal Park, Judith seemed to know we wouldn’t find any agates. So she bought a jar full of them in an antique shop for about $5. In the gravel landscaping outside the restaurant where we were going to meet for lunch she sprinkled the agates.

We entered the restaurant and joined our group sitting at a window table. Everyone reported on her morning escapades.

Finally someone asked if we found any agates. Of course I said, “Yes!” Then I slowly retrieved my miniscule pebble. Everyone laughed.

Then Judith said that we must have gone to a bad beach because agates were so prevalent in the area they get mixed in with ordinary landscape rock. She pointed out the window and said she bet they were right out there. Roz and I looked at each other then got up. Sure enough, we found a handful.

It turns out it’s harder to find Lake Superior agates in Lake Superior than it is in the Brainerd area. I have a friend who kayaks in central Minnesota lakes and reaches down and plucks out two-inch “lakers” on a regular basis. Another friend consistently finds them in Northeast Minneapolis. You can find them, too; you just have to know where to look.

Lake Superior agates are the oldest agates in the world. They formed over a billion years ago when molten lava flowed onto the earth’s surface. Stranded gas bubbles became air pockets where agates formed.

Rising and falling water tables left trace minerals that created the bands: iron ore caused the reddish stripes and silica hardened into layers of white quartz. Each band represents a different mineral deposit.

Then glaciers scraped the land, exposing the concealed agates. In 1969, Lake Superior agates were designated the Minnesota state gemstone.

Since that trip I have indeed found Lake Superior agates on the North Shore. Look for them after a storm, without sunglasses that can alter natural colors, and near the water’s edge so the rocks are wet.

The Wisconsin side of the lake doesn’t have many, but Wisconsin Point’s beaches are worth the drive for tumbled glass and sandstone.

Agates also can be found all over the metro area. Look in riverbanks, road cuts, digging sites or when you’re planting flowers in your own backyard. Keep the sun ahead of you so light shines through the translucent rock. But for even better results, visit ZRS Fossils & Gifts (3018 Lyndale Ave. S.) or the Enchanted Rock Garden (6445 Lyndale Ave. S., Richfield).

My girls trip has since disbanded, but Duluth/Superior is still my favorite destination. I continue to search for and learn about Lake Superior agates, but I apparently I need to sharpen up my practical joke skills. Thanks Judith!


Enjoy Sunday brunch on the patio at Lyn 65 (6439 Lyndale Ave. S.), located next door to the Enchanted Rock Garden (Sunday brunch, 10 a.m.–2 p.m.; rock shop open Sundays, 11 a.m.–4 p.m.)