I've never used vermiculite and i could only find "horticultural vermiculite" by Hoffman at Walmart. I put my gecko/dragon eggs on this other Walmart brand reptile bedding that said it could be used for incubating eggs, but i checked on the eggs recently and they have small brown spots on them now...mold? i definitely did not add too much water to the medium i do know that much. But now i wanted to transfer them all onto this vermiculite. It says its natural for flowers and all, just wanted to make sure it didn't have any chemicals or anything that would harm the eggs as to i don't see anything added to it on the bag.