I have a beautiful square spill vase, which is a beautiful pale blue aqua marble effect. It is square, and stands approx. 3.8" tall. It came from a collection of Sowerby glass, but on close inspection I don't think it is Sowerby. The base has a sqaure design on it, it stands on 4 ball shaped feet and the tops of each corner have a half ball on them. There is a logo in the base which is hard to make out, but to me it looks like a crown. The colour and marbleing is EXACTLY like a hexagon shaped piece I have which is definitely Sowerby, but this square vase appears to be made by someone else. Any ideas or suggestions would be most welcome.