The Process of Agate Hunting
Agate hunting is a timeless activity along many shores around the world, including the North Shore of Minnesota. With their beautiful bands on the inside coming in an incredible array of colors, it’s no wonder why the agate is the states’ official gemstone. Duluth Pack even bases its very own chocolate rocks off the agates and stones found along the North Shore. Now is the perfect time for you to get out there and hunt for these beautiful collectible gems yourself.
Agates were formed billions of years ago when a massive lava flow solidified and formed the bed of Lake Superior. As air pockets formed in those bubbles, mineral-rich water would seep into the pockets and form layers. These solidified layers formed agates, the colors of which depended on the composition of the minerals in the waters that formed them. When the last ice age hit, the glaciers scraped against the ancient lava sheets, which caused the agates to break off and be scattered here along Lake Superior’s shores.
The beaches of Lake Superior are the perfect place to find agates. They are mostly found in areas that have exposed rock gravel. Try to check near and crags or cliff faces (if safe to do so) as these are the best habitat for the gems.
Of all North American gemstones, agates can be the most difficult to find. They are difficult to identify due to their more neutral colors on the outside. They can easily be looked past or mistaken for a rock or piece of gravel. When searching for agates, you should look closely for any banding on the rock, as well as a glossy sheen or texture. Also, make sure that you’re looking based on size, agates are not very large. They usually come between the size of a penny to the size of a walnut.
Now, what time should you be looking for agates? The best times are right after a storm on the lake, this allows for new rocks and ground to be kicked up on the shore. Try to look in the water or where it is wet. Agates stand out when wet because the bands become translucent and the gem itself will glisten.
Now that you’ve found your agates, what are the best ways to clean and polish them? Many times when you find agates they may have a calcite buildup on the outside. This is just mineral buildup that has attached itself to the agate. Don't worry, it will be easy to get rid of. All you need to do is combine one-part vinegar and one-part distilled water, place your agates in the solution and soak for 12 hours. Once that is complete, you can pour milk over the agates to neutralize any acid from the vinegar, then scrub the gems with a sponge. After that, any calcite should come off with ease.
The last step to bring out the best possible look for your agates is to tumble them. A rock tumbler is an easy way to get your gemstones to that desirable shine. You may find some agates smooth and with that beautiful sheen already. That is because the constant rolling of the waves and sand over hundreds of years has smoothed out the stone. If they're still rugged, a rock tumbler is the best solution.
You can find a basic rock tumbler online for around the $50 mark. The way it works is you put your agates inside and add an abrasive in (like sand or a powder safe for your machine). By doing this, you’re shortening the hundreds of years it would take those agates to smooth out and cut it down to a few days. After a time, you replace the courser abrasive in the tumbler with a finer one and ta-da. Smooth and beautiful gemstones for you to collect.
Happy agate hunting, friends!