I was picking through some silver flatware and came across a spoon stamped "silver metal". looks like silver, tarnish looks like silver. Filed and tested with 70% nitric acid = green active reaction (not creamy white) with a bit of brown fume, calms to a very nice siver nitrate blue. I dabbed a bit onto filter paper and it looks like silver nitrate blue (not green). The file groove did not discolor like plate silver though. The spoon has no other markings. Any thoughts? Is it likely silver?