It depends on the detector. Most Minelabs (with the exception of the GPX series) have a hard time with small gold such as chains and should definitely be in All Metal, but some White's detectors, such as the V3i should have no problem detecting it in the high frequency (22.5KHz) and accepting VDI numbers into the ferrous range down to -40. I have seen chains come up in the -20 range on the White's
You should not need to dig for a bracelet unless it was dropped years ago. Even so, chains tend to stay very close to the surface. and a probe should do the trick.