Please help me identify a central Minnesota rock
I've found a few of these rocks, which I consider beautiful, in the central Minnesota region, near The Ripley Esker. I imagine they are a Lake Superior creation but I can't find this particular rock anywhere I research regarding Minnesota rocks & minerals, or even other regions.
The main stone is usually a beach-worn round shape (not always round, but always beach-worn seeming) and a dark color- shades of brown, dark green, or burgundy. They have a solid color, never mixed with any other shades. The sizes vary but the biggest I've found is maybe 2" in diameter, but the majority I've found are much smaller. The main stone is packed with tiny round rocks (maybe inclusions but doubtful) that are various colors all over the main stone, ranging in dark shades of burgundy, rust, browns, grays, greens, neutral colors. They usually are almost flush with the main stone from the wear. But some of these I've found with the tiny rocks sticking up only slightly. They are always smooth, never jagged, not a chert at all, more like a basalt perhaps, which is true of the main stone and the tiny stones in it. I believe these tiny round things are rocks rather than inclusions because some of them I've found have a few tiny round stones missing and they leave round holes where they once sat. The inset stones are always roundish. And the main stone is always packed full of them. The tiny round stones are only on the surface of the main stone, not inside. I can't even think of a similar rock to describe them with, except rocks with actual inclusions, but they are still so totally different from those or anything else I've seen. They are not beautiful amongst other rocks, in gravel say, but they are so unique that they are intriguing. And they are rare to find in my experience. Their colors are very neutral and earthy. You have to be almost on your hands and knees to see them.
My theory is perhaps it might have been created when the glaciers were pushing through and pulverized tiny stone into surface rock. Some pieces broke free and over time everything became well worn and circular. But I have no idea. I'm just a Rockhound, albeit I am fairly knowledgable of Minnesota's rocks & minerals. This particular rock has be perplexed and stumped.
I am hoping someone might know what this is. I sure wish I could post a picture of it. It's hard to really give great, accurate description. If anyone can help me on a way to post a pic, please let me know. But mainly, if anyone can help me identify this rock, please help. I am dying to know what this rock is and what its all about. I appreciate any help at all!
Bob's Rock Shop rocks!
Thanks to all!!
From Paula Kruschke - September 19, 2013 at 21:59:23