There is a very small location where Staurolite can be found in Minnesota. Staurolite, otherwise known as Cross Rocks, are a neat little collectible. There is a small beach below the Blanchard Dam where they can be dug out of the river or on shore. A 3/8 screen is VERY helpful in recovering the stones. Most are found as singles but sometimes you find twinning, or more than one crystal growing in the same space. What you are after is those very few that are found that make a perfect cross. And the bigger the better.
I was able to visit this site for about 90 minutes and found a few hundred little pieces, a few with twinning and only 2 that would count as a "Cross Rock."
But that is fine as there is no need to find them all. It is a much better practice to get a few then leave the rest for others.
Searching for the Cross Rocks in the Mississippi River south of Little Falls, MN!