Mendip Hills In some areas the limestone and the dolomitic conglomerate have been mineralised with lead and zinc ores. From the time of Roman Britain until 1908, the hills were an important source of lead. These areas were the centre of a major mining industry in the past and this is reflected in areas of contaminated rough ground known locally as "gruffy". The word "gruffy" is thought to derive from the grooves that were formed where the lead ore was extracted from veins near the surface. Other commodities obtained included calamine (zinc ore), manganese, iron, copper and baryte. The eastern area reaches
Metallic color the metallic finish of such paints was added using fine aluminum powder and pigment rather than actual gold. The use of metallic colors is not limited to those colors that approximate the appearance of actual metals. In some instances, it has been noted, "[b]eetles with bright metallic colors are made up into tie pins and cuff links". One popular modern use of metallic colors is for automobiles, which use metallic paint to achieve a particular shine. Such colors "are made from a combination of different pigments and aluminum flakes that have different weights and particle sizes". Crayon-maker Crayola has manufactured