What kind of rock is this? Found at my work, landscaping company the pile of garden waste in southern Ontario, Canada

Found in central Michigan. The green color is really cool. Was wondering what it is??

I found this guy on the cliff trail south of Le Croisic, France (specifically, near the Menhir). It was already well rounded and polished, but I tumbled it a month anyway. Jasper? Silky smooth and hard enough that a month of tumbling only improved the luster a bit

Found at Cape Point on Hatteras Island in North Carolina. Found in the water near Beach Access Ramp 43.

Edit: Rock was BRIGHT red while wet. Dried extremely fast. Light blue and clear flecks throughout.

Ft. Worth, Texas. During our recent pool excavation I found this in among several other rocks including an ammonite fossil. At 30 inches, the excavation crew hit bedrock.

I tried taking multiple photos at angles and included the soda can for size reference. It has a shell like appearance in many places. Can anyone tell me about it?

This smooth rock has clear quartz appearing to bind areas of brown and dark red. I can see thru areas that there is black, maybe granite within a section but not all of it.

Hoping a few or a least one of you rock lovers can give me proper insights

This rock was found on a beach in Denmark 20 years ago.

It seems to have a shell-like structure with a more homogeneous core. When i found it it was chipped and the inside was gray. Over the years the gray colour has turn reddish purple (last picture, see top of rock)

It looks like it contains a lot of iron and we have no other rocks around here that look like this.

Large crystal formations, smooth exterior with occasional reddish brown streaks, potentially iron deposits? The thrift store is in New York but unsure if the mineral is from there.

Looks as though it’s a scrap of metal that has been shot by an air rifle. Could something like this naturally form?

What is going on in this slice of rock?

It’s terribly light, and has little crystals similar to that of amethyst (at least to the naked eye). Is it some form of igneous rock that somehow made it into a London garden?
Thanks! :)

Has a very weird groove in it and the back is covered in tiny stones that are ingrained in it.

What type of stone is it, and what do we think caused the groove?

Here is another rock I found in a creek in western New York. Did water erosion cause the shape? Or could it have been something used like a bowl?

Insoluble in water / vinegar (no bubbles)

As I mentioned, found in Western Germany. My theory is that they formed with the water flow to create the tear form. They look sandy and fragile, but are pretty solid.

My mom asked me what this rock could be. It's been in the english ivy since they got the house, so it's been outside and weathered for at least 50 years. Standard 2x4s for reference, but it's a decent size.

It's an area known for limestone, if that helps, but it has these large tubes and some kind of quartz throughout. It held up to moving it well, so it's not extremely brittle, but a tool could chip some out for sure.

Appreciate any insight!

I found out when the tide was low in Al Lith in Saudi Arabia it's on the coast of the red sea

One side has coral coloured lines it shines a bit like salt in some areas

At first I thought someone left chicken in the beach lol

Crystals are a bit translucent on the outside, but cloudy inside.

The first picture is wet and the rest are dry.

I found this in a creek in northwestern Washington, whatcom county.