If translated from Czech, for metallurgical glass, google translates gives hutní sklo, a phrase I always understand to mean "hand shaped at the furnace" or similar, nothing to do with metal in the glass.
It is interesting that the candleholder is recognised as a Karlovarske design. My idea that there ought to be a vase and bowl is still viable too. the implication is that they may have an old catalogue showing it, without design attribution maybe?
My topas bowl-vase above was seen by the Moser historian and was viewed as not Karlvarske Sklo, as "there is no signature and Karlovarské sklo always used a signature on the bottom. That is why we suppose it was not produced by karlovarské sklo either." This is not my experience of Karlovarske sklo output. But I am not to disagree particularly as Moser try hard to be helpful on this ambiguous aspect of the history of Moser glassworks.
(They helpfully identified an amethyst piece of glass I have, of more normal cut style Moser, as being Moser, unsigned, "indicating it was made before WWII.")
For my bowl-vase with bubbles, the Moser historian noted quite sensibly that it is made from "solid glass" implying not blown as the sides are very thick indeed, about 4cm, not really possible to blow and so it would have been cast into some kind of mould maybe....
good to hear that this candleholder of yours has been identified at least as a Karlovarske Sklo product. Well done Moser for the help!
Robert (bOBA)