There are many techniques. Most use colors already made and mix them, some add minerals to the glass to change them.
It is tricky to do if it is a formed shape. The trick is to melt the frit and the surface of the form, not melting the inside of the form. It is fast.
Gold and silver melt at different temperatures, the working temperature of glass will burn off the fume, which is why most fume is incased
Yes and no. Not all devitrification is the same. Many times it happens when glass is bent with a cold surface and warm inner. This will cause devint to happen. Another cause can be overworked glass. This is just what it is and can not be less worked for many techniques. To fix this one …
No, only the green UV glass has uranium.
It is all a little differnt based on the sand used, and yes that comes from the region. It also depends on the ratios of additions that will also effect the end product.
Here you can learn a lot about glass. Murrine Milli
This is done by putting in a lot of lines on a big tube, then pulling it down smaller, then it seems to have even more lines.
Only US 33 makes raw borosilicate glass, and it is not good. Elev8 Premier uses Shott glass, made in Germany by the people who invented boro.