My son is taking chemistry in school and he tells me he's grindingÌýrocks but I've yet to see any rocks. Does this possess a danger?Ìý
This should be a harmless activity in that all that is happening is an automatic way to grind down minerals that often result in polished and sometime quite beautiful stones. ÌýBe clear that some tumblers are "on" for weeks in order to polish the stones so electricity costs are a mild consideration.
