Polish glass, made by Hortensja.
Silver salts are used to create the surface decor (which are also used in Mdina, that's the connection you spotted).
Not the most common of things to find. This range, which comes with a blue background and another in amber, were only made to order.
However they are a kind of tribute to an older style, and I can't for the life of me remember what, but there are discussions here about it. I'm sure it was Flying-Free did all the research on that.
Not having your glasses in my mitts, I might be tempted to wonder, but it is far more likely to be Hortensja than the older one.
Both are lovely. I've had an interest in this since I first found it, I'm a sucker for things using silver salts.