Follow Us On Twitter Follow Us On Instagram Friend Us On Facebook

Lake Superior Agates

Lake Superior AgatesAbout Lake Superior Agates

Lake Superior Agates were formed 1.2 billion years ago by volcanic activity.  Gas pockets in molten lava filled with mineral deposits (like ferric iron, quartz or calcite) as the years passed by. The pockets that were filled with quartz-rich deposits gradually crystallized into concentric bands (known as chalcedony) to form agates. Over time (we’re talkin’ a billion years) the agates were freed by water and ice from the lava rocks that they were buried in.

Lake Superior Agates are red, orange and sometimes yellow colored and are very different from other types of agates found throughout the world. The oxidation of iron created the beautiful red colors. The color between the agate’s bands is determined by the amount of oxidation that took place when the rock formed.

Agates range significantly in size with most of them being small, pea-sized stones. However, some weigh over 20 pounds (about the size of a bowling ball)! There are a few different types of Lake Superior Agates, with the most common being the fortification agate which displays the well-known banding pattern.

How to find Agates

When you’re searching for agates among other rocks, you’ll want to look for a few clues:

Where to go

Agates can be found along Lake Superior’s North Shore, inland along hundreds of lakes, almost anyplace with gravel or exposed rocks and the gravel banks of nearby streams and rivers. Prime Lake Superior beaches along MN-61 that we recommend include:


FUN FACT: Back in 1969 the Lake Superior Agate beat out other types of rocks like Binghamite yellow silkstone, Thomsonite and Pipestone to become Minnesota’s state rock.



Cascade Vacation Rentals offers the largest selection vacation rental homes, cabins, hotels and cottages on the North Shore of Lake Superior. Our rentals cover a large area from Duluth to Grand Portage and inland up the Caribou Trail, Gunflint Trail and throughout Cook County. View rentals by location (DuluthTwo HarborsSchroederTofteLutsenGrand MaraisGunflint Trail) or category type (pet-friendlylarge homes, inland lake homes, etc) at



Check back often for updates on where to go and the top things to do on your next North Shore visit.

This entry was posted on Friday, July 22nd, 2016 at 1:52 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.