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Antimony is a chemical element with the symbol Sb (Latin: stibium, meaning "mark") and atomic number 51. A metalloid, antimony has four allotropic forms. The stable form of antimony is a blue-white metalloid. Yellow and black antimony are unstable non-metals. Antimony is used in flame-proofing, paints, ceramics, enamels, a wide variety of alloys, electronics, and rubber.

Properties
Antimony in its elemental form is a silvery white, brittle, fusible, crystalline solid that exhibits poor electrical and heat conductivity properties and vaporizes at low temperatures. A metalloid, antimony resembles a metal in its appearance and in many of its physical properties, but does not chemically react as a metal. It is also attacked by oxidizing acids and halogens. Antimony and some of its alloys are unusual in that they expand on cooling. Antimony is geochemically categorized as a chalcophile, occurring with sulfur and the heavy metals lead, copper, and silver.

The abundance of antimony in the Earth's crust is estimated at 0.2 to 0.5 parts per million.

Applications
Antimony is increasingly being used in the semiconductor industry in the production of diodes, infrared detectors, and Hall-effect devices. As an alloy, this metalloid greatly increases lead's hardness and mechanical strength. The most important use of antimony is as a hardener in lead for storage batteries. Uses include:

Batteries
antifriction alloys
small arms, buckshot, and tracer ammunition
cable sheathing
matches
medicines, antiprotozoan drugs
plumbing
soldering - some "lead-free" solders contain 5% Sb
main and big-end bearings in internal combustion engines (as alloy)
used in the past to treat Schistosomiasis; today Praziquantel is universally used
used in type metal, e.g. for linotype printing machines
used in pewter
Antimony compounds in the form of oxides, sulfides, sodium antimonate, and antimony trichloride are used in the making of flame-proofing compounds, ceramic enamels, glass, paints, and pottery. Antimony trioxide is the most important of the antimony compounds and is primarily used in flame-retardant formulations. These flame-retardant applications include such markets as children's clothing, toys, aircraft and automobile seat covers. It is also used in the fiberglass composites industry as an additive to polyester resins for such items as light aircraft engine covers. The resin will burn while a flame is held to it but will extinguish itself as soon as the flame is removed. Antimony sulfide is also one of the ingredients of safety matches.

In the 1950s, tiny beads of a lead-antimony alloy were used for the emitters and collectors of NPN alloy junction transistors.[citation needed]

The natural sulfide of antimony, stibnite, was known and used in Biblical times, as medicine and in Islamic/Pre-Islamic times as a cosmetic. The Sunan Abi Dawood reports, “Muhammad said: 'Among the best types of collyrium use is antimony (ithmid) for it clears the vision and makes the hair sprout.'”

Stibnite is still used in some developing countries as medicine. Antimony has been used for the treatment of schistosomiasis. Antimony attaches itself to sulfur atoms in certain enzymes which are used by both the parasite and human host. Small doses can kill the parasite without causing damage to the patient. Antimony and its compounds are used in several veterinary preparations like Anthiomaline or Lithium antimony thiomalate, which is used as a skin conditioner in ruminants. Antimony has a nourishing or conditioning effect on keratinized tissues, at least in animals. Tartar emetic is another antimony preparation which is used as an anti-schistosomal drug. Treatments chiefly involving antimony have been called antimonials.

Antimony-based drugs such as allopurinol and Meglumine, are also considered the drugs of choice for the treatment of leishmaniasis in domestic animals. Unfortunately, as well as having low therapeutic indices, the drugs are poor at penetrating the bone marrow, where some of the Leishmania amastigotes reside, and so cure of the disease - especially the visceral form - is very difficult.

A coin made of antimony was issued in the Keichow Province of China in 1931. The coins were not popular, being too soft and they wore quickly when in circulation. After the first issue no others were produced.

History
Antimony's sulfide compound, antimony (III) trisulfide, Sb2S3 was recognized in antiquity, at least as early as 3000 BC. Pastes of Sb2S3 powder in fat or in other materials have been used since that date as eye cosmetics in the Middle East and farther afield; in this use, Sb2S3 is called kohl. It was used to darken the brows and lashes, or to draw a line around the perimeter of the eye.

An artifact made of antimony dating to about 3000 BC was found at Tello, Chaldea (part of present-day Iraq), and a copper object plated with antimony dating between 2500 BC and 2200 BC has been found in Egypt. There is some uncertainty as to the description of the artifact from Tello. Although it is sometimes reported to be a vase, a recent detailed discussion of reports it to be rather a fragment of indeterminate purpose.

Antimony was first isolated by Geber (721-815), a Persian (or Arab) alchemist. The first European description of a procedure for isolating antimony is in the book De la pirotechnia of 1540 by Vannoccio Biringuccio, written in Italian. This book precedes the more famous 1556 book in Latin by Agricola, De re metallica, even though Agricola has been often incorrectly credited with the discovery of metallic antimony.

A text describing the preparation of metallic antimony that was published in Germany in 1604 purported to date from the early fifteenth century, and if authentic it would predate Biringuccio. The book, in German, was the Triumph Wagen Antimonii (Triumphal Chariot of Antimony), and its putative author was a certain Benedictine monk, writing under the name Basilius Valentinus. Already in 1710 Wilhelm Gottlob Freiherr von Leibniz, after careful inquiry, concluded that the work was spurious, that there was no monk named Basilius Valentinus, and the book's author was its ostensible editor, Johann Thölde (ca. 1565-ca. 1624). There is now agreement among professional historians that the Triumph Wagen was written after the middle of the sixteenth century and that Thölde was likely its author.[18] An English translation of the Triumph Wagen appeared in English in 1660, under the title The Triumphant Chariot of Antimony. The work remains of great interest, chiefly because it documents how followers of the renegade German physician, Philippus Theophrastus Paracelsus von Hohenheim (of whom Thölde was one), came to associate the practice of alchemy with the preparation of chemical medicines.

According to the traditional history of Middle Eastern alchemy, pure antimony was well known to Geber, sometimes called "the Father of Chemistry", in the 8th century. Here there is still an open controversy: Marcellin Berthelot, who translated a number of Geber's books, stated that antimony is never mentioned in them, but other authors[who?] claim that Berthelot translated only some of the less important books, while the more interesting ones (some of which might describe antimony) are not yet translated, and their content is completely unknown.

The first natural occurrence of pure antimony ('native antimony') in the Earth's crust was described by the Swedish scientist and local mine district engineer Anton von Swab in 1783. The type-sample was collected from the Sala Silver Mine in the Bergslagen mining district of south central Sweden.