Heavy metals are here treated as light metals and, in general, are not further considered. The heaviness of naturally occurring metals such as gold, copper, and iron may have been noticed in prehistory and, in light of their malleability, led to the first attempts to craft metal ornaments, tools, and weapons. All metals discovered from then until 1809 had relatively high densities; their heaviness was regarded as a singularly distinguishing criterion. From 1809 onwards, light metals such as sodium, potassium, and strontium were isolated. Their low densities challenged conventional wisdom and it was proposed to refer to them as "metalloids" (meaning "resembling
Metals Service Center Institute Marti is Vice President of Research and Technology; and Ashley DeVecht is Director of Communications. Metals Service Center Institute The Metals Service Center Institute (MSCI) is a trade association and nonprofit organization based in Rolling Meadows, Illinois, in the United States. It was established as the American Horseshoe and Heavy Hardware Association in 1909 and was subsequently known as the American Steel Warehouse Association, then the Steel Service Center Institute. The organization's members are primarily metal service centers that inventory and distribute metals for industrial customers and perform first-stage processing. MSCI has approximately 400 members operating from 1,500 locations primarily