Is there such a thing as a poisonous rock?

Answer 1

I suppose the answer could be yes. There are "rocks or elements found naturally that could be harmful, but all in all, it's probably best not to pick up random rocks anyway! Rocks are not likely to be poisonous in their natural state. There may be elements in them that can cause one to be sick, but the quantity that would have to be ingested would be pretty high. Note that many chemicals in their pure form look like rocks and can be very poisonous, but are not normally found occurring in a natural state. Such things as arsenic can be quite deadly, but you don't find it laying around except in toxic waste sites. Lead and Mercury not good things to ingest either.