This sweet flower decorated sterling pin is enamel on a guilloche sterling ground.
The reverse shows 'Sterling' and 'BM Co' which is the hallmark of the Breadner Company of Canada. This pin was made after 1930 as at that time the BM Co mark came into effect (prior to that it was the Breadner Mfg. Co).
It is hard to see because of reflection but in between the petal on the left side and the ones above and below it, there is a small area of shiney sterling silver left unpainted by any enamel. It is part of the design and absolutely meant to be that way.
The pin measures approx. 1 3/16" in diameter.