Use of Bakury andesite in the production of Dark-Green bottles

Georgian glass container works produce bottles that are primarily dark green. Pyrite cinders or ferrochromium slag are used as colourants but because their composition is variable they do not ensure colour stability and the required shade of products. The use of Bakury andesite as a colourant was investigated on the properties of glass. Two glass compositions were synthesised. In place of pyrite cinders, andesite was used in a glass mixture with calcium aluminate, and to replace ferrochromium slag, andesite was used with magnesium aluminate. Crystallisation, viscosity, uniformity of colour, chemical and thermal stability, and strength of the glasses were studied. The results indicate that andesite can be used to colour container glass a dark green. Its use eliminates several components from the mixture and gives a higher quality product.