I found this a wee while ago, and thought it was lovely, but I'm clueless about what it is. I suspect Czech.
The base is polished completely flat and is a very neat looking, round-cornered, square shape. I suspect it is arrised too, but only very slightly.
There are four upright "dents" around the base going up into the body, the shape is very simple, but because of the positioning of the dents and the thickness of the glass and the use of the colours, it all works together to make it appear far more complex than it is - and a nightmare to photograph!
The colours are a greyish lilac encasing a pale grass green.
Any help appreciated.