Different Glass Colors information

The Metallic additives in the glass mix can make various colors. Here cobalt has been added to produce a bluish colored attractive glass Metals and metal oxides are added to glass during its manufacture to change its color. Manganese can be added in small amounts to take away the green tint lent by iron, or in higher concentrations to provide glass an amethyst color.

Similar to manganese, selenium can be used in small concentrations to decolorize the glass, or the higher concentrations to impart a reddish color. Small concentrations of the cobalt (0.025 to 0.1%) will yield blue glass. The Tin oxide with antimony and arsenic oxides make an opaque white glass, first used in Venice to make imitation porcelain. 2 to 3% of the copper oxide produces a turquoise color. Pure metallic copper produces an extremely dark red, opaque glass, which is at times used as a substitute for gold ruby glass. Nickel, depending on the concentration, will produces blue, or violet, or even black glass too.

Adding titanium makes the yellowish-brown glass. Metallic gold, in very small concentrations (around 0.001%), will makes a rich ruby-colored glass, while lower concentrations will makes a less intense red, often marketed as "cranberry". Uranium (0.1 to 2%) can be added to give glass a glowing yellow or green color. Uranium glass is normally not radioactive enough to be dangerous, but if ground into a powder, for example by polishing with sandpaper, and inhaled, it can be carcinogenic. Silver compounds (especially silver nitrate) can make a variety of colors from orange-red to yellow. The way the glass is heated and cooled can notably affect the colors shaped by these compounds. The chemistry concerned is complex and not well understood.