Topic: Need help to identify glass goblets with hexagon dark purple stem

[Bells]

Hello!


We have been trying to identify the logo etched into these very tall goblets of various sizes (full set has white and red wine goblets, champagne flutes and sherry glasses)..

The stems are long and thin, hexagonal in shape, with a dark purple to almost black inside the stem with the hexagon glass outside of it. 

The base has a symbol etched into it, that we have not been able to identify anywhere.  It is of a C with a crown on top.

Any help would be greatly appreciated. 

[Bells]

Just to add to the above..

The glasses are from at least the 1980's..