Vintage Sterling Silver Brooch with Blue Cabochon Center

This is a sumptuous-feeling vintage brooch set with a rich blue cabochon and marquise shaped clear rhinestones among stylized leaves. It measures nearly 2.25 inches in length and 2" in width. It is mid century. By the look and feel I believe it is sterling but I do not see a marking. The flowers have a slight golden patina and the reverse is silver. Gorgeous piece!