Editing Stained glass (section)

===Red glass===
* Metallic [[gold]], in very low concentrations (around 0.001%), produces a rich ruby-coloured glass ("ruby gold"); in even lower concentrations it produces a less intense red, often marketed as "[[cranberry glass]]". The colour is caused by the size and dispersion of gold particles. Ruby gold glass is usually made of lead glass with tin added.
* Pure metallic [[copper]] produces a very dark red, opaque glass. Glass created in this manner is generally "flashed" (laminated glass). It was used extensively in the late 19th and early 20th centuries and exploited for the decorative effects that could be achieved by sanding and engraving.
*[[Selenium]] is an important agent to make pink and red glass. When used together with cadmium sulphide, it yields a brilliant red colour known as "Selenium Ruby".<ref name="Illustrated Glass Dictionary"/>