They do look a bit like that, yes. If you want that multicoloured or black = dark blue or dark green or dark aubergine look then that would be freshwater as far as I know
It looks to me like several pearls have been glued together. You can see a silvery line in the valleys which are joins which I am guessing is some sort of caulk, filler or glue.
Superglue - especially gel superglue - every time. Epoxy is just not reliable enough and does not have a dissolver. Superglue needs moisture to set btw
The pearl is not natural.It is a low quality freshwater pearl, inappropriately set. The silver is below commercial sterling 925 standard and not sellable at all in Europe as it contains nickel.
Not sure that the Tahitian pearl actress thing is 100%. Most of the pearls stuck in customs, people are in prison and it all went totally nacred.
Did anyone hear anything from the OP?