:::::: Are the two smaller pictures the same piece just showing the front side and the back side of the same piece? :::::::::::::::
:::::::::::::::: Are there hallmarks on that center piece in the center of the golden chain circle? (maybe that center piece is a modern 18k gold addition to the chain? That looks more like 18k gold and kind of more modern looking? :::::::::::::::
i dont think that 56 is 18 k its more intenese golden colored because its gilded with 22 k gold. the initials are МТ also womans head and Δ everywhere womens heads .