Certainly an unusual piece, and nothing in either of Barrie Skelcher's books to help. Mould blown - 175mm tall, and 5.5mm thick at the top rim. Not easy to describe it's decoration...the main body is pale greenish, with alternating vertical spirals of pale crimson colour and what appears to be flecks of ash in between, which thin out towards the top. You can see the reaction to the torch. A lot of small bubbles 0.5mm up to 2.5mm, very general throughout the body,with one large one of about 7mm! Enough base wear to put it back into the c.1920 - 40 area, but not the water staining that you might think had it been used for flowers for any length of time. Anyway, I'm stumped, so any thoughts are welcome please, and thanks for looking.