Ruby Glass
A unique technique for coloring glass in a rich red hue
Ruby glass is a decorative glass with a deep red color, obtained by adding gold or other metals to the glass batch. The color is achieved through strict adherence to chemical processes: gold particles are dispersed in the mass and begin to glow only when heated to a certain temperature. This method was especially popular in the 18th–19th centuries, and items were valued for their luxury and rarity.
Even royal dynasties competed to possess such goblets, and sometimes craftsmen deliberately kept the recipe secret. Legends tell that once a master threw a copper coin into the furnace instead of gold, and the glass turned murky green! Ruby glass has always been considered an object of special status and a decoration for collections.