Brass than in brass produced by cementation. These may be "natural alloys" manufactured by smelting zinc rich copper ores in redox conditions. Many have similar tin contents to contemporary bronze artefacts and it is possible that some copper-zinc alloys were accidental and perhaps not even distinguished from copper. However the large number of copper-zinc alloys now known suggests that at least some were deliberately manufactured and many have zinc contents of more than 12% wt which would have resulted in a distinctive golden color. By the 8th–7th century BC Assyrian cuneiform tablets mention the exploitation of the "copper of the mountains"
Industrial metal metal with industrial music in the late 1980s Pigface, formed by Martin Atkins and including Ministry drummer Bill Rieflin, emerged as an industrial metal collective of sorts, participating with many figures from the noise rock and industrial worlds. Nine Inch Nails, the "one-man-band" formed by Trent Reznor, brought the genre to mainstream audiences with albums such as the Grammy-winning "Broken" and the best-selling "The Downward Spiral", accompanied by their groundbreaking performance at Woodstock '94. The rivethead subculture also developed at this time, along with the so-called "coldwave" subgenre, which encompassed Chemlab, 16 Volt, and Acumen Nation. Some electro-industrial groups adopted