How Do You Polish Lake Superior Agate?
The Lake Superior agate is found on the shores of the lake in Minnesota, Wisconsin and Michigan, and is Minnesota’s state gemstone. Lake Superior agates were formed from lava flows and the formation of the Lake Superior basin early in Earth’s history, according to Minnesota Department of Natural Resources. Today, hunting for agates is a popular hobby for residents and vacationers along Lake Superior. Their finds can be polished for use as a gem in jewelry or other decoration. Select enough agates to fill a rotary rock tumbler barrel at least half full and no more than 3/4 full. Weigh them on a scale, then return them to the tumbler. Add coarse grit to the tumbler. Add approximately 1 tbsp. of grit per pound of rock. Add water to the tumbler so the water is even with the highest layer of agates. Close the tumbler and turn it on. Run the tumbler for one week before checking it. Turn off the tumbler and open it after a week. Remove the agates, which will still be rough, and wash them well
