Imperial Glass Twisted Optic Green Vase. This is a lovely green or ultramarine vase circa 1927-1930, possibly made by Imperial Glass. This flower vase has a twisted optic pattern of swirls or spirals that go in the direction of right or counterclockwise. This vintage vase measures 6-1/2” tall with a 3-1/2” opening on top. Could also be Duncan Miller Spiral Flute. In execellent condition with some straw marks.