Big rectangular studio vase signed "R..., 80" for ID

I would kindly ask for your help once more in identifying this big and heavy studio pottery vase (appr. 26 cm tall).
The signature starts with "R...", it is dated 1980, and in addition there is a small round brass button worked in the base with a stamped R.
Bought in Vienna, Austria, if that helps in attribution ;-)

Thanks,
Michael