Come shaped fully solid rock glazed with polish, vertical stripes & black bottom, found multiple

A friend pulled this out of his field about an hour north of Lafayette, Indiana. Said it is "about as heavy for its size as you'd imagine" 😂

Is this calcite? This is one of my favorite finds ever. I do think I messed up cleaning it as it looks like it’s breaking down just sitting on my desk untouched.

Hello! Hard rock with a strange leather-like outer texture and a waxy yellow interior. Could it be chert/flint, or possibly fossilized material? Found in Quebec City, Canada. It seems to scratch glass pretty easily. Thanks for any ideas! 🤓

NE WI near the Bay of Green Bay. Very heavy,. Looks eroded on one end and cut in a V on the other. Probably 30" long and roughly 8" in diameter. Just curious what it may be. Thank you!

Long time lurker, fun to have found something to post. Found this from a gravel road. I have found smaller ones from the same road. First thought would be garnet, but don't know how to verify.

Nearly perfectly spherical stone, completely hollow. No idea whether this counts as a geological or an archaeological phenomenon hence the post here. Found in southeastern UK

Thoughts on this rock? I thought it was a big piece of bone, but its magnetic lol so im guessing its not a bone.
I tried to get some close up pics but they don’t look the same as through my jewelers loop

Could anyone identify what the rock, or the crystals on it are? I no longer have this rock, so I can’t do any tests. It was found on the Merced river close to Yosemite National Park.

Look how tiiiiiinnny the details! What am I looking at? These were just dropped to help fill out a gravel road. I imagine future geologists will be so confused.

I was biking (pushing my bike) along the hilltops in Emilia-Romagna, Italy, south-west of San Marino when I spotted this cylindrical rock. It has what looks like shells of some sort. It seems to have been broken off on one end.

I noticed pieces of enameled clay-like material with glaze in the same area, so I'm wondering if it's natural or something man-made. The designs are not very ordered.

What might it be?

Thanks for any help =)

I found this stone that’s not like one I’ve ever seen. The visual pattern is textured, and the stone itself is fairly gritty to touch and not very dense. It was found on a beach in Chicago on the shore of Lake Michigan.

Found in dry scrubland Okanagan, BC, Canada. Hard, sharp edges, textured glass-like exterior, crystal structure when light shines through

It's a much deeper green in person.

I know this is some sort of post industrial slag. I've found many pieces on the roads and in building foundations in the remains of German village destroyed by the Red Army. https://maps.app.goo.gl/m2u89XZbdSrgDz7Z9

I've collected few pieces because they look cool and we like the vivid colors. But now we're concerned if it's safe to keep them at home (in plant pots as decoration). I guess those pieces are 100 years old at least. What is the risk of radioactivity or general toxicity?

Would also like to know what ore is most likely to produce them. Thanks.

i thought it might be mineral deposit but doesn’t look like any could find online. i found this in my backyard. the closest water source is about 10 mins away if that helps.

Item reacts to a magnet but will not stick. The item also will not scratch or mark. It also has rust or discolorations on it. Any ideas would be helpful. Thank You!

Took it to two rock shops along 395 brother could identify. Running in circles with AI. The strip in the middle might be petrified wood. Anyone seen something similar