How do you test it DD? hydrogen sulfide? nitric acid followed by a chloride salt (precipitates insoluble silver chloride whilst then the nitrate is highly soluble as are most nitrates.)
Reminds me of a great silver find I had. Was searching, of all the places to find a hoard of silver, in a dumpster. Looking for copper or lead, had absolutely NO idea that I was going to find silver, a couple of pieces in silver and either ivory or whalebone , the very least precious being silver buttons for a coat, minus the coat. Thought...hmmm...those have a familiar slight warm golden overtone to the typical bright shiny metallic appearance of bulk metals, it isn't copper, it isn't lead, too heavy for aluminium....is that what I think it is...'
Took everything I found home, after systematically dismantling, piling up in stacks and picking through each and every little trifle, every rubbish sack of old cloth and costume jewellery, to find a rolex, broken but the scrap value for the diamonds and the gold has to be worth having, nabbed each and every one of those buttons unless there may have been one or two I missed buried inside old clothing, the other quite definitely silver and antique silver, plus the silver-ivory or silver-whalebone items. Very definitely nice stuff. The buttons were newer, fresher and less oxidized/less surface sulfide layer, but taking advantage of that characteristic dark tarnish silver can take on, and produced some hydrogen sulfide gas, carefully of course, given it has similar toxicity to hydrogen cyanide, in terms of rapidly knocking down the electron transport chain and inhibiting cellular respiration within mitochondria, choking cells to death on the molecular level despite being in an oxygenated atmosphere. Unlike cyanide, which with first inhalation of an alkyl nitrite ester aka 'poppers', the shitty recreational drug, that acts as a rapid vasodilator and helps deliver nitrite to the system as fast as possible to keep you alive long enough to administer intravenous sodium nitrite (not nitrAte, nitrIte, and finally sodium thiosulfate to complex the liberated cyanide and allow its excretion. I know of someone on one of the chemistry forum who was accidentally poisoned with cyanide, and he would have died within minutes, had he not known what to do, managed to keep his head screwed on in the right direction despite the circumstances, keep calm as possible and prepare and intravenously inject a dose of sodium nitrite. then prepare and inject a second shot of thiosulfate in order to complex the cyanide he'd almost killed himself with. Got to admire courage like that in a hobby chemist, I've gotten myself out of some tough ass scrapes intact, but that takes fucking balls of steel. )
H2S is similarly nasty, if not more insidious, because it sneaks up, foul smelling, like rotting eggs, but also paralyzes the olfactory nerve, so the sense of smell is, if the hydrogen sulfide doesn't kill you outright, deadened temporarily, leading the unwary or those unaware of the insidious tendency of H2S to ninja people and whack them when they think it's gone away, when in reality the situation is just that the individual is unable to detect the odour, And unlike cyanides, the cyanide rescue protocol doesn't work for hydrogen sulfide.
But it IS handy at times, such as for artificially producing tarnish on suspected silver, so as to determine a true or false status. So I could tell I had indeed found goodies beyond what I hoped to possibly find in a dumpster in the stuff that wasn't hallmarked, as I had not at the time, either any nitric acid or any nitrate salt or other nitro or nitrito -compound with which to prepare any, and needed doing one way or the other. No aqua regia as a result either, but I'm not the type to go by a philosophy 'if in doubt go without', or similar, and I had to figure out a way to wing it, which turned out to be roasting metal powder, iron, pretty sure, and sulfur dust to produce a metal sulfide, roughening the surface of a button, wetting it with water, and exposing it to a stream of hydrogen sulfide. Of course needing great care in the proceedings,given the nature of H2S and it's talent for killing people, but the tell-tale blackening told me just what I needed to know, and even better, just what I wanted to hear too, I.e that the effort gone to and use of H2S was justified and that I was indeed sitting on a pile of silver. And the best bits of it antique.
