Question

How is stained glass made?
a.
adding metallic oxides to sand and ash or lime, then infusing at high temperatures
b.
adding metallic oxides to salt, then infusing over time at low temperatures
c.
adding metallic oxides to sulfur, then infusing at high temperatures
d.
adding metallic oxides to sulfur, then infusing at low temperatures

Answer 1

a.

Stained glass is made by adding metallic oxides (colorants) to molten glass, which is made from silica (sand) together with soda (historically plant ash) and lime, and melting them together at high temperatures. The specific metal oxides determine the colors (e.g., cobalt for blue, copper for green, gold for ruby).