This green tint is often the source of questions when glass is used in a situation where the edges are exposed. Looking into the glass from the edge displays the green tint most prominently.
The tint occurs from the iron in the glass. If you were using a piece of glass to protect a beautiful piece of furniture, you would notice that the color of the furniture would be tinted green while looking through the glass.
The iron becomes an ingredient of the glass to act as a lubricant. Most glass is drawn along on top of a moltant layer of tin. The liquid quality of the tin is why the glass can be so smooth on both sides, since it is difficult to have bumps in a liquid surface. The iron level in the glass varies from manufacturer to manufacturer depending upon their recipe for their glass. But most glass contains these levels of iron that act as a lubricant to permit the glass to be easily drawn.
Some types of glass are made without or with very little of this iron and therefore do not appear with a green tint. Consolidated Glass uses Starphire, a PPG product, for applications where the green tint is not desirable such as a store front, handrail, product display or to protect fine furnishings.
If you are interested in glass without the green tint, contact our Sales department for more information on low-iron or Starphire glass.
These sample photos show outdoor daylight after traveling through several feet of glass containing normal amounts of iron on the left, and low-iron glass on the right. Viewing the glass from the edge this way exaggerates the green tint of the glass, but does serve as a visual guide to the 'whiter' and 'clearer' nature of the low-iron product. Notice also how much 'darker' the normal iron glass on the left is.