This must be one of the most unusual pieces of 1950s Skrdlovice.
Not the shape, which I think is a Zemek design, PN 5530 (a little slimmer than my other one). It stands 13 cm tall.
But it has an intriguing semi-opaque, slightly lustrous finish. It looks almost like there was a layer of opalescent glass around it, but I guess it is just a thick coating of something like silverchloride (one of our lovely glass-chemistry knowledgeable co-members can explain it, I am sure).
The only other pieces with this finish I ever saw are these two beautiful signed Emanuel Beranek vases auctioned in 2008 (>> Link 1
, >> Link 2
It has the bigger silver/yellow label I have on two other late 1950s pieces.
Maybe Robert can add some more info