I doubt it. Heroin isn't weighed on regular digital scales because it's such a fine powder and weighs next to nothing. It would be almost like trying to weigh talcum powder, if I can make that analogy. My best guess is that the residue was retrieved from something typically used to consume the drug. If snorting was the method of delivery, then it was likely found on a mirror, cd case, counter, straw, dollar bill, or something of that nature. If the method of delivery were intravenous, then a syringe, a spoon, a piece of cotton or cig filter found in the trash, etc. If smoked, then a piece of foil, or a straw.