Period 6 element heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China. Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent other metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when newly made, but often seen in air with a pink tinge owing to the surface
Bench jeweler same for jewelry casting. The cast pieces will likely need a variety of work done to them, including filing to remove the skin left from casting and prepare for polishing, straightening parts, rounding and sizing rings, and assembling many various parts together using solder. Although the method used is called soldering, it is actually a form of brazing, using "solders" of the metal being worked, i.e. gold solders for gold pieces, silver solder for silver pieces, etc. All of this is the work of bench jewelers, who at this level are sometimes known as production workers in some arenas. In