The heat could be decay heat from the decay of a radioactive material. Not sure what this is though. If this is from Russia, then I'm not surprised. Used fuel rods from nuclear reactors have been found lying around in the nature near power plants and submarine stations.

Those aren't rocks - they're goat testicles.


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Yeah, if it's from space, there is a good chance it is radioactive

This is fake, I mean it's not a rock but a piece of Iodine. And I bet that all the burns (which are stains in reality) will disappear within few hours. And to make all things clear - Iodine sublimates with red - violet fume.
I'm not sure if it's the problem of educational system, or people are more stupid nowadays but I was able to identify this "mystery" at first glance.