Examples of these colloidal particle colourants include gold, which imparts a ruby red colour, and selenium, which offer shades from pink to intense red. The colloidal particles scatter light of particular frequencies as it passes through the glass, causing colouration. These particles are often formed as the result of treatment with heat, forming what are known as ‘striking colours’. This simply means particles of a substance that are suspended throughout the glass. There’s more on what causes the colour of transition metal ions here.Īnother manner in which colour can be introduced is by formation of colloidal particles. The metal ions absorb certain wavelengths of light, varying depending on the metal, leading to the appearance of colour. This is usually achieved by the addition of metal oxides to the glass. The first involves introducing transition metal or rare earth metal oxides to the glass. A number of other types of glass are also possible, such as lead glass, but are beyond the scope of this post.Ĭoloured glass can actually be produced in a number of ways, but there are three main methods. Additionally, it’s used in flashlight lenses, allowing a higher percentage of light through compared to plastic. It has a greater durability, combined with greater chemical and heat resistance, which leads to its use in laboratories, as well as in cookware. As well as silicon dioxide, this type of glass contains boron trioxide. It’s not, however, the only type of glass we can make.Īnother type, which those who work in science laboratories will be familiar with, is borosilicate glass. It’s used for a range of purposes, including bottles, containers, window panes and drinking glasses.

The vast majority of the glass we use on a daily basis is soda-lime glass this is primarily a mixture of silicon dioxide, calcium oxide (lime) and sodium oxide (soda). There are actually different types of glass for different purposes.

This graphic takes a simple look at a few of these, and the colours they impart.īefore discussing the cause of colour in more depth, it’s worth discussing the chemical composition of glass itself. The origin of these colours is something we don’t give a lot of thought to, but a range of different elements are responsible. Coloured glass is something that’s commonplace in our lives, from the green of wine and beer bottles, to the red, yellow, and green of traffic lights.

Green glassdoor