u/ChicoryChicken

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)

The red parts can be scratched by iron keys, but not the grey-white ones.

I really like the colors, could this be polished?