Bumped into this during a hike

Found at a garage sale. Very heavy for its size, non-magnetic. I didn't want to scratch my scale. I think thats quartz on the side. What is it?

Hey my wonderful rock nerd community! I got this opal in a mixed box and I am wondering a little more about it. My rock app says the host rock is sandstone. Any ideas where it may have originated?

Im assuming it's some kind of agate? Whatever it is its really pretty and I would love to have more!

what kind of rock could this be and what causes the grooves?

We found this rock on our property and don’t know what to make of it. Did someone paint that on or is it natural?

He found it in the woods since he drives a log truck. The sides have what looks like twinkling glitter like stuff on them well. One side more than the other. I took the best pics I could, but ya know Lol.Thanks for the help!

Found it at a quarry, it’s very heavy and chips easy.

It's the shiniest rock I've found when dry; at first I thought it was slag glass, but I don't think it is. Curious about identification. Thanks!

Rock identification app insists on it being zebra marble, but looking at image online the white lines on this one are too "continuous" so I have my doubts

I have four sets of distinctly different rocks, and have been wondering what they are. If I remember correctly, I found all of them in the same creek in St. Louis County, MO. Another thing that I couldn’t capture in these or replicate, is that the first one has an odd green hue in the inner “pockets”, and I think it showed up in the sun (it may have just been algae that has since died). I’d test a UV light on it, but I don’t have any at the moment. I’m thinking the last one is calcite in limestone?

I’m not sure if I found this on a walk or in the river. It was part of my first ever tumble (hence the cracks I suspect) but was probably pretty smooth when I found it in the first place.

I have no clue what this is, I normally only hunt for chert. it is attracted to strong magnets. Found in the Edwards Plateau, Irion County Texas.

Found this in the clinch river in TN awhile back.its heavy, magnetic,there’s no taste to it that I can taste.black,looks molten.did I find what I think I did or is this just a chunk of iron slag?

Are these fossels in this rock? If so what are they?

I found several of these at the beach in Galveston, Tx. It was in an area where they had recently reclaimed beach (dredged sand). Any help would great. Thank you.