Antimony is the chemical element with atomic number 51, symbol Sb. It is a member of the group of pnictogens. With properties intermediate between those of metals and non-metals, antimony is, with arsenic, a metalloid of the fifth main group of the periodic table. It is a weakly electropositive element. The electronegativity according to Pauling is around 1.9, while that of As is around 2.
The simple antimony body is a polymorphic, toxic and carcinogenic metalloid, like arsenic8 (with which it is often associated, for example in lead-based ammunition).
The antimony isotope 121 represents 57 percent of the estimated antimony mass, it is the only stable isotope with antimony 123.
There are around twenty radioactive isotopes, whose atomic masses range from 113 to 134. Among these relatively poorly known isotopes, antimony 125, an artificial radionuclide used as a radioactive indicator, sporadically present in the environment, very little studied, except on a few polluted industrial sites23.
The literature mentions (bio) methylated forms (at low concentrations), which could be more bioassimilable23.
Its environmental kinetics is poorly understood, but it seems not very mobile in the soil, and not very bio-assimilable for plants. It does not seem to be bio-accumulated nor to be the subject of bio-amplification in the food webs23.
In organisms, its toxicity seems to be linked to its affinity for thiol groups (irreversible binding to important enzymes). Its possible ecotoxicity is poorly understood. According to IRSN, "the potential for trophic transfer has never been studied" 23.
Antimony 124 is a source of gamma rays. Associated with beryllium it has been used to diverge certain nuclear reactors24.
Occurrences in natural environments, mineralogy and geology
The clarke amounts between 0.7 and 0.2 ppm or on average 0.5 g per tonne25. Antimony is a rare element, ten times less common than arsenic. It is however present in more than a hundred minerals.
Antimony is even more rarely found in nature in the form of a native element, metallic Sb called native antimony often with traces of arsenic, iron and silver. This mineral is sometimes alloyed with native arsenic, such as stibarsen or arite. Breithauptite is a natural nickel antimonide.
For life cycle analyzes and apprehension of the depletion of so-called abiotic resources, antimony is the unit used since 2004 to quantify consumption of raw material26. The conversion of the raw quantities to their antimony equivalent or kg of antimony involves the total quantity of raw material available on earth. So there are estimates in milligrams of antimony per kilogram, in milligrams of antimony per liter ..., to estimate the rarity of a described entity.
magnesium bismuth manganese chromium cobalt titanium
Tungsten vanadium niobium indium molybdenum antimony
rhenium germanium zirconium cadmium hafnium