Opal with red enamel.

dimensions to follow (also poor main image to be replaced )

Possibly Rudolf Schrötter, Inwald, Rudolfova hut before 1958 probably 1930s, pattern number 1/0021. The balls are less pronounced than the tea set q.v. but the colour of the glass is an exact match.

Unfortunately the upper surface is either very worn with ingrained dirt or this is remnants of another type of graduated decoration. As the red dots are also worn and the underside near perfect I would suspect long usage under a flower pot.

Similar designs to Boule in US (Imperial Candlewick 1930s) Germany (VEB Kugelrand 1970s)

ref http://www.glassmessages.com/  and pre 1958 Rudolfa Hut catalogue