Georgian glass decanter

Georgian glass decanter of the Prussian style with mushroom-shaped, star cut stopper.  Two triple cushion rings to neck and diminutive diamond cut pennants to shoulder. Alternating panels of horizontal prism cuts and leaf-shaped pattern beneath vertical fluting around base.  Unpolished pontil mark and radial fluting to base.Possibly Waterford.
Irish, circa 1780 - 1800