I agree with Keith. It is very much like one I have (see pics); plain design but with light iridescence.
I also have a pair which are the same as one taller vase illustrated in Cyril Manley's book Decorative Victorian Glass, item 16, page 54/5 which he thought were Richardson's and known in the trade as "opal iridescent". He said that "other oddly shaped vases are occasionally found". This was with other examples in his book now normally believed to be Kralik rather than Richardson or some other British maker.
My vase shown here is 12 cm (4 3/4 inch) high and 13 cm (5 1/8 inch) wide at the base. The (mostly) smooth finished pontil area seems quite typical of the few examples I have seen.