No, it is not a very good machine on fine dainty gold chains (assuming that was the type "chains" you were referring to). NO discriminating detector (at least not wet salt beach varieties) are going to be good at tinsel thin gold chains. Perhaps a few 2-filter discriminators would do better than a power-house explorer or excaliber, but you will find those don't perform too well in the wet mineralized salt.
And if you REALLY want to not miss ANY tinsel thin fine gold chains, get yourself a beach pulse machine. You'll get through ANY type minerals, will get EXCELLENT depth, and won't miss ANYTHING. But you will hate life if you get on a nail-riddled beach, because they don't discrimination (or the ones that claim to, will loose depth when you do the iron disc. tricks). The minute you dig a bobby pin at 1 ft. deep, is the minute you'll want to go back to an excal, explorer, or whatever.
With the excal, if you listen real close to the flitty whispers (like super low foil) you can get some thin gold chains (especially if they're balled up). But any machine that's going to excell in that department, will have its own set of drawbacks. So it's a compromise sometimes.