Morphologically diversified sulphide mineralization has been found in No. 301 and 302 coal seams (Westphalian B). The main sulphide is pyrite which forms veinlets cross-cutting the sedimentary fabrics of the coal. encrusts the cellular structures and intergrowths with oxysulphides. https://allfixelectricales.shop/product-category/water-chamber-air-break-nut/