History

(Gr. anti plus monos - "a metal not found alone") Antimony was recognized in compounds by the ancients and was known as a metal at the beginning of the 17th century and possibly much earlier.

Sources

Antimony is not abundant, but is found in over 100 mineral species. It is sometimes found natively, but more frequently it is found as the sulfide stibnite.

Properties

Antimony is a poor conductor of heat and electricity. Antimony and many of its compounds are toxic. 
A Periodic Table of the Elements at Los Alamos National Laboratory