Antimony is a chemical element; it has symbol Sb (from Latin stibium) and atomic number 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. The earliest known description of the metalloid in the West was written in 1540 by Vannoccio Biringuccio.
Antimony
Native antimony with oxidation products
Stibnite, China CM29287 Carnegie Museum of Natural History specimen on display in Hillman Hall of Minerals and Gems
The Italian metallurgist Vannoccio Biringuccio described a procedure to isolate antimony.
A chemical element is a chemical substance that cannot be broken down into other substances by chemical reactions. The basic particle that constitutes a chemical element is the atom. Chemical elements are identified by the number of protons in the nuclei of their atoms, known as the element's atomic number. For example, oxygen has an atomic number of 8, meaning that each oxygen atom has 8 protons in its nucleus. Two or more atoms of the same element can combine to form molecules, in contrast to chemical compounds or mixtures, which contain atoms of different elements. Atoms can be transformed into different elements in nuclear reactions, which change an atom's atomic number.
Estimated distribution of dark matter and dark energy in the universe. Only the fraction of the mass and energy in the universe labeled "atoms" is composed of chemical elements.
Portrait of Robert Boyle, c. 1740
Title page of The Sceptical Chymist, published in 1661
Portrait of Isaac Watts by John Shury, c. 1830