This recently acquired bon bon dish in Hobnail Blue Opalescent is from a Southern estate. The Blue Opalescent was made from 1940-1970s. There were three distinctive colors of Blue Opalescent making them difficult to match up. The darker blue was made in the first issue in 1940 until the late 40s when the formula was changed. It then became a richer, paler blue. Then in the 1960s it was reintroduced and changed again to a darker blue, but not as dark as the original. This particular piece is from the 1950s in the richer, paler blue. It is 6" in diameter with a double crimped edge. It has a wide band of opalescent blue on the outer edges and is simply beautiful.