Could use some help identifying

I picked these up at a reuse store today but have no clue what material it even is. They are very warped but thought maybe I could lay them out in the sun and they would flatten out because they seemed to be some sort of plastic or resin. They were dirty- had paint specks and small pebbly dirt stuck to them that I thought I could clean off but that is proving difficult. I tried scrubbing with a toothbrush and soapy water. The material is very hard and doesn’t scratch, but I cannot get the dirt off. It’s almost as if it melted into it a bit but I don’t think it is. Not sure how to clean it, but when it dried it developed a white film appeared that goes away when wet so I may have ruined the coating. It seems to scrub off though. Did I ruin it?
when in the shade, the background looks black but when the sun shines through it turns a deep bright red. All the colors change but that is the most dramatic. I was not expecting it and don’t know how I feel about it but it’s kind of cool.

Does anyone know what this is and how I can clean it? It is two sheets of what seems like some sort of plastic or resin put together. The back piece is clear with a bumpy pattern. It almost seems like someone added that later but maybe not.

 

looks like stained glass that's had a hard life........ maybe been in a fire?

 

Could be….

 

Agree with faux stained glass... that's spent too much time in direct sunlight.
JMHO but, from the sounds of it, it's damaged beyond repair.

 

I've seem similar before. They look like they've been done in by hard living. If worse comes to worst they can sit somewhere and look pretty.

 

Maybe you could use some acrylic paints over the white film areas to spruce it up.

 

It might not stick, but glass or metal paint would if the area was clean. Even nail polish sticks to glass as long as you don't scratch at it.