This is a very attractive vase, clear glass, flaring shape, 145 mm wide by 155 mm high, ground and polished pontil, very thick clear base, with a fine gentian-blue thread spiralling down the vase, and ending in a large dot.
I am wondering if it could be by Bertil Vallien during his time with Swedish Boda?http://glassgallery.yobunny.org.uk/displayimage.php?pos=-1063
I have tried to inset a similar shaped vase in the photo, by Vallien, patterned in blue. The other inset is a Vallien bowl with a similar spiral thread ending in a large dot. I have a feeling that I have seen this pattern of spiral thread ending in a large blob or dot, as a typically Swedish motif, in other glass.
This is a quality piece, but has three tiny bubble blemishes, which might have precluded a signature if it came from Boda or another major Scandinavian maker. The blue thread is external, but at the top it disappears under a casing of glass around the rim.
Anyway, it is very nice to look at, but a positive identification would be an added bonus, as always.