Hi, I picked up this strange looking item a while ago. It's got a wavy rim, five prunts around the bowl, a hollow stem with a spiral wrapped round. It has rings on the surface of the foot. The Pontil scar is fairly smooth. 16cms tall, 15cms across the bowl. I can't find anything like it, any idea of age and from where it came from please. Reminds me of some drinking glasses I have seen . Thanks Cheryl