i was able to grab a couple of these rocks, from an entry road for truck drivers
to drive over so they wouldnt get stuck in the mud. i grabbed a few to see if i
could id. there are im sure over 1000 or so stones and entry is no longer
being used and if theyre tank friendly ill go back and get some that have more
character. the owner thinks they might be lime stone but doesnt know for sure.
theyre extremely hard, i tried to break the larger one with a small crowbar and
hammer and it was barely chipping. i tried to scratch it with my buckknife but
looks more like the metal it being left on the rock, wont scratch with a nail.
no fizz from vinegar. i tried to use the rock id website but couldnt figure it out.
if anyone else has any ideas let me know.
If you can't scratch it with steel, it's probably safe.
I think in some areas, limestone is pretty commonly used for aggregates, gravel, cobbles and such, which may be why the owner thought they were limestone. But limestone is fairly weak, it scratches easily, and shouldn't be to hard to break up.
Wouldn't scratch? Hmmmm, I actually would have guessed limestone (or maybe conglomerate -- fancy word for nature's concretes and cements) but limestone shouldn't be harder than your knife. When testing hardness, you're trying to see if you can make a little scratch, rather than if you can break or chip off a piece.