r/whatsthisrock

Any idea what this is? It's cylindrical with white rings around it. Not super heavy for its size.

Definitely has basalt and quartz with possible amethyst.

FYI, look like the striations are filled with the red clay known to the area.

But no idea what this is, I asked the person who brought it, she said I have to find out within 24 hours

My little cousin found this by the side of the road in Delft, Netherlands, and is curious what it is. Someone must have dropped it there, because we only have thick sediment layers here and no rocky soils in a wide radius. Help appreciated.

I guess less what is this rock and more what’s in this rock?

Found on the Oregon Coast, north of Lincoln City. I'm assuming the Clear spots are calcedony that found air bubbles but I've never seen them like this. I thought the usually needed cracks to reach pockets that would lead to seems, not bubbles like this.

Solved! Amygdaloidal Basalt with chalcedony

A polished surface with brown banding, presumably featuring quartz and amethyst crystals. Possible origin?

I was seeing smaller rocks with this design and I thought it was because horse's shoes were scratching the rocks. But then I found this big one and I could see more clearly that the white marks weren't scratches from horses. Is this ancient sea life? Or just a regular rock?

Riverbed, western Washington.

This rock has a bunch of grooves and a deep worn surface. It also smells oddly fishy and smokey? None of the other rocks I found smell like this.

What is going on here?

Massive 20kg rock and about a foot wide. From South West UK. Does not fizz when I put vinegar on it and absolutely will not scratch with a knife.

Found in Texas in some landscaping rock. Knife does not scratch it. It's got some sparkle and areas that are similar to what agate looks like

Found in a creek in central Ohio

Found in a volcanic canyon. I'm thinking it's some kind of Jasper. Just looking for other opinions.

It’s feels very solid and heavy. The chipped smooth areas are glasslike but I’m pretty sure it’s a mineral. Any guesses?

I can't dig a hole anywhere on my property here in east central Mississippi without hitting tons of these. They are everywhere. They break pretty easy and the inside are kind of grainy looking.

Hi! I did home tests, not sure if I can post again, but I'm including more photos and what I found out. I also found lil "amber" Cabochons as well in my pile of loose gemstones.

- ACETONE TEST: on one part, it became a little bit tacky.

- UV LIGHT : it's greenish yellowish? ( Bonus cabochons and diamonds under UV light )

- HOT NEEDLE: it's very fragrant, i love the scent 😂. Doesn't smell like burning plastic.

- WEIGHT: surprisingly light at 475g, and yes, I made sure the entire thing was on the scale, no cheating by resting on the table. ( Bonus: cabochons were 2g each )