Why is Glass Green?

You may have noticed that glass has a green hue to it. Ever wondered why? The simple answer is that it contains Iron.

Ordinary glass, which is made of a soda-lime base, contains iron-oxide.  For those of you into the chemical side, that’s FeO, also called ferris oxide. When thin, you don’t notice any color, but as this ordinary glass gets thicker, it takes on a green tinge from the iron-oxide impurities which are common. You notice it more so when the glass is in front of something white, so the green shines through more: such as white subway tiles.

If that green hue bothers you, and you are willing to spend more money, Low-Iron glass is your answer.

Low-Iron Glass

Low-iron glass is a type of high-clarity glass that is made from silica sand with very low amounts of iron. This low level of iron removes the greenish-blue tint that can be seen especially on larger and thicker sizes of glass. Although the name ‘standard clear glass’ makes you think they are very clear, they are not. The reason for less clarity in standard clear glass is due to more iron content in them. Ordinary clear glass has about 10x as much iron content.

Low-iron glass will continue to have a color cast, with each cast differing by manufacturer. Keep in mind, the smaller the piece, the less amount of cast.  The larger the piece, the greater the cast. The cast is still very minimal. Low-iron glass has increased light transmission capacity. They remain transparent and non-reflective when you look at them from any angle or edge.

Low-iron glass is referred to by a number of different product names.  Some of the most common names include: Starphire, Krystal, Ultrawhite, and Optiwhite depending on the manufacturer. Some major uses of low iron glass is in solar panels, fish tanks, and camera lenses.

In our showroom we have Low-Iron glass right next to clear glass with white subway tiles, so you can really see the difference.  If you are in the market for a new Shower Enclosure and have light colored tile, Low-Iron glass might be just for you