Antimony

Antimony is a brittle silvery-white metal, of value both in the arts and medicine. Its symbol is Sb (derived from the name of its ore Stibnite) having atomic number 51. This chemical element is a metalloid used in alloys, usually with lead, such as pewter, type-metal, and Britannia metal.

It was known even in ancient times. The naturally occurring black sulfide of this metal had been in use as the cosmetic kohl. Stibnite is the most common ore of the metal which was also called antimony or antimonium in the middle ages.