Speculum metal metal mixtures usually contain two parts copper to one part tin along with a small amount of arsenic, although there are other mixtures containing silver, lead, or zinc. The knowledge of making very hard white high luster metal out of bronze-type high-tin alloys may date back more than 2000 years in China although it could also be an invention of western civilizations. Such metals were used in sculpture and to make more effective mirrors than the more common yellow easily tarnishing bronze mirrors. In that era mirrors of speculum metal, or any precious metal, were rare and only owned by
Industrial metal industrial metal techniques in this period, including Skinny Puppy (on their "Rabies", co-produced by Jourgensen), and Front Line Assembly. British band Pitchshifter, formed in 1989 by brothers Jon and Mark Clayden, also started as an industrial metal band. The band later included elements of drum and bass. Frontman JS mentions: Industrial metal's popularity led a number of successful thrash metal groups, including Megadeth, Sepultura, and Anthrax, to request remixes by "industrial" artists. Some musicians emerging from the death metal scene, such as Fear Factory, Nailbomb, Autokrator and Meathook Seed, also began to experiment with industrial. Fear Factory, from Los Angeles,