Opium is the sap from the pod (ovary) of the poppy plant. Its a kind of latex-ish goo that turns brown as it dries. There is no way it would ever crystallize, and even if it did it wouldn't be clear.
It could be purified alkaloids from the sap, but its unlikely that anyone would do that when there is such a market for opium.
So no, you don't have opium. It could be an opiate chem of some sort, but if the guy could get away with selling you comething like that as opium, he could get away with selling you salt or anything else about as easily.