Silver chloride salts were added to glass because they change the colours of the glass with heat.
The salts themselves melt whan added to glass (thanks, AdamA!) trailing over it, and when it gets hot enough, the silver and chloride ions seperate - chlorine is a gas, it will create bubbles.
Silver makes clear glass yellow -> ochre, depending on the concentrations, and it makes blue glass, greener - this is how all the random coloured effects are achieved in Mdina.
During the additions of various casings of making a piece, silver metal ions can do various things, depending on the heat and what molecules it comes into contact with.
Sometimes, if the glass came away from the metal blowing iron slightly, gaseous silver ions escaped then condensed on the outside of the glass - giving rise to what is described as Mdina iridesence - it's a trail of silvery bluey yellowey mirror like stuff on the outside of the piece - you can see it on the ebay link.
Other times, if the outer casing is particularly thick - the silver molecules do form a "cloud" inside the casing itself - it's very bluey - almost a sort of electric blue - but quite pale.
Now your pics have appeared, I can see there is the silvery iridesence on the top of the weight in the third image.
Topic: Omg The Holy Grail And i Missed IT Mdina crizzle stone.goin cheap??? (Read 1939 times)
