Brass zinc, especially between the Islamic and Byzantine world. Conversely the use of true brass seems to have declined in Western Europe during this period in favour of gunmetals and other mixed alloys but by about 1000 brass artefacts are found in Scandinavian graves in Scotland, brass was being used in the manufacture of coins in Northumbria and there is archaeological and historical evidence for the production of calamine brass in Germany and The Low Countries, areas rich in calamine ore. These places would remain important centres of brass making throughout the medieval period, especially Dinant. Brass objects are still collectively
Group 6 element 1924. For about a century after its isolation, molybdenum had no industrial use, owing to its relative scarcity, difficulty extracting the pure metal, and the immaturity of the metallurgical subfield. Early molybdenum steel alloys showed great promise in their increased hardness, but efforts were hampered by inconsistent results and a tendency toward brittleness and recrystallization. In 1906, William D. Coolidge filed a patent for rendering molybdenum ductile, leading to its use as a heating element for high-temperature furnaces and as a support for tungsten-filament light bulbs; oxide formation and degradation require that moly be physically sealed or held in an