This is a very nice pin from B.S.K. B.S.K. is the mark of The B. Steinberg-Kaslo company which manufactured jewelry form 1948 until the early 1980's.
This pin measures 2 1/4" by 1 1/4". The metal is bright, all stones are present, it is in excellent condition.
It will look great on you! A wonderful addition to or start on your vintage costume collection!
As always, all reasonable offers are welcomed and considered.