r/whatsthisrock

Found this while digging a hole in my yard in the Sugar House area of Salt Lake City. It was about 3 feet underground, and I remember going through dirt and a pretty distinct clay layer while digging.
It was originally packed/covered with dirt and clay. After soaking it in water and gently brushing it, I uncovered a ton of small crystals and crystal-lined cavities. The part I can’t figure out is the really straight, angular, almost geometric-looking structure running throughout it.
The photo with the measuring tape is from before I cleaned it. The close-ups are after soaking/cleaning, although there’s still some clay down inside the cavities.
Any idea what this is, what the crystals might be, or what would cause it to form like this?

Best idea I’ve heard so far is that some kind of crystal like pyrite grew inside of the rock and then broke out. I’m not totally convinced that this isn’t man-made, but what could it possibly be for? Any other ideas?

As you can see there are some layers that are translucent grey and then others that are solid colours that change between layers. No cluw what it is but i think it looks pretty cool.

Looks slightly more green-ish in real life :)

Is this an amethyst or a flourite crystal?

Colorwise it reminds me of my other flourite crystals,but the shape makes me think of an amethyst.

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Hi together,

Found this little at the beach. ( Baltic sea; Dahme Germany)

What do you think? Glas?

Cheers

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! 🤓

Found in creek near kettle river in South Okanagan, British Columbia

Hello everyone, I found this rock whilst out for a walk in the Sebino peat bogs in northern Italy. I was particularly struck by its colour and by the fact that two of its corners have smooth fractures, whilst the other two have a very subtle zigzag pattern that’s easy to feel when you touch it. Could you tell me what sort of stone it is?

I’m wondering if it might be flint...

It has the same hardness as hyaline quartz

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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.

Can anyone help with identifying please? I've been told jade and jadite but unsure. It was given to me and I have no idea of it's origin. Thanks

Hello. i bought this on a beach in puerto vallarta, Jalisco in Mexico. The man stated it was genuine obsidian and tried to burn it with a lighter to show it’s genuine. I’m not sure tho bc aren’t you supposed to be able to look at the sun thru true obsidian? As that is what was used in mesoamérica to view the eclipses. this stone is extremely opaque and black all around.

It doesn't sound quite like a regular rock when you set it down but don't know what exactly it sounds like. It sounds almost glassy or like slate but feels like a smooth, normal rock. Very hard to touch but seems like it would break if dropped. It was found in the woods near my house a long time ago (don't remember finding it). I will answer any questions but don't know what else to provide right off the bat!

It can't be scratched by a knife and weights quite a lot for its size. Also, if someone can tell me how it formed and why it's so wavy, I'd appreciate it!

(In the first photo it's wet, in the second it's dry)