To make coloured glass, the colouring pigment is added to the raw materials while preparing the batch for its manufacture. The whole mass is heated till it becomes homogeneous.
The colouring pigment may consist of metallic oxides, finely divided metals, carbon, salts of metal, sulphur, etc. Different substances which are used to produce different shades of colour. It may be noted that different quantities of the same substance may also impart different colour to the glass.
The coloured glass is used for various purposes such as artificial precious stone, window panels, fancy articles, decorative tiles, etc.