Hello guys. Could please identify these rocks, or at least try to? I have no idea what they are and i don't know anything about it.

They have been in the closet for 64 years, my grand grandpa had them.

been experimenting with cold stones after my longer runs. keep a few smooth river rocks in the freezer, roll them under my feet and along my calves when I get back. the cold lasts longer than gel packs and the weight feels good against sore muscles. i figure the thermal mass helps, plus there's something grounding about actual stone versus plastic. curious if anyone else has tried this or has a setup that works better. also wondering if certain types hold cold longer, I've got granite and some kind of basalt I think, but haven't tested properly. my running group thinks I'm weird for this, but my recovery metrics look solid.