Raw glass is made all over on planet earth. Glass is basically just sand. The big secret is where does the raw sand, or cullet come from? There are rumors out there that the China color is used for some cullet in American colors. Big thing is if it is re manipulated here in the USA, it is well, made in the USA.
In the boro world.
Clear
Shott is the most used as it is super clear and super clean. GERMANY
Simax is made IN Czech Republic
Pyrex made in USA and Japan
Color
Northstar – USA
Glass Alchemy – USA
Greasy Glass – USA
Boro Batch – USA
Elev8 Butter – USA