Sketchy patina

Hi all,

I am repairing a bracelet for a friend of mine - it’s an interesting
affair, cast sterling with half of the connecting rings as part of
the casts (I find that weird. Is it common practice? Anyway…)

The links are lighthouses, with little windows, and everything.
(So.cute). When I fixed the broken link, the patina in the recesses
(windows, etc.) was removed in the 2 links affected by the repair.

However, when I pickled the piece, the remaining patina stayed put.

So… what is this mystery patina, and should I go about re-applying
it? Remove it all the the torch, and start over? Is it LOS?

Thanks bunches, you’re all a wealth of

Lynn in Chattanooga, Tennessee