This pin has an "s" in a square as its sole marking. The only other maker that I know of that indicates sterling with an "s" in a square is Mikimoto, but in every other example I've seen by that jewelry maker, it is also accompanied by the "M" in a clamshell for the maker's mark. My piece does not have the "M" hallmark. Can someone help me identify the maker? Would it be Mikimoto, -- did they alone use "s" in a square for sterling? -- or were there other, possibly Asian, jewelry makers of the same time period who used the "s" in a square to indicate sterling? Any help would be greatly appreciated.