Operation of sand or gravel pits, basalt / porphyry, clay (ordinary), crushing and breaking of stone for use as a flux or raw material in lime or cement, manufacture or as building material, road metal or ballast and other materials for construction
Manufacture of protective safety equipment (fire-resistant and protective safety clothing, linemen���s safety belts and other belts for occupational use, cork life preservers, plastics hard hats and other personal safety equipment of plastics, fire-fighting protection suits, metal safety headgear and other metal personal safety devices, gas masks etc.)
Manufacture of jewellery of gold, silver and other precious or base metal metal clad with precious metals or precious or semi-precious stones, or of combinations of precious metal and precious or semi-precious stones or of other materials