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 fiber of nylon is wrapped clockwise and the other end is wrapped counterclockwise around the metallic yarn. The most commonly used nylon is either 15 denier or 20 denier, but heavier deniers are used for special purposes. The most common uses for metallic fibers is upholstery fabric and textiles such as lamé and brocade. Many people also use metallic fibers in weaving and needlepoint. Increasingly common today are metallic fibers in clothing, anything from party and evening wear to club clothing, cold weather and survival clothing, and everyday wear. Metallic yarns are woven, braided, and knit into many fashionable fabrics and