I found this strange spherical stone in Gillette Wyoming. I have no idea what it is. Please help. These are recent pictures of it. It’s heavy, I see small minerals that catch the light in it, very bumpy, spherical, doesn’t seem to be magnetic, I was falling down a deep trench and kicked it up at the bottom. Area was sand, sage, and small cacti. (https://i.stack.imgur.com/p2Bbz.jpg)
This is a so called Moqui Marble. A spherical concretion formed by sand and iron based minerals like limonite. 

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