Editing Tellurium (section)

==History==
[[File:Martin Heinrich Klaproth.jpg|thumb|upright|alt=Oval black and white engraving of a man looking left with a scarf and a coat with large buttons. |[[Martin Heinrich Klaproth|Klaproth]] named the new element and credited [[Franz Joseph Müller von Reichenstein|von Reichenstein]] with its discovery]]

Tellurium ([[Latin]] ''tellus'' meaning "earth") was discovered in the 18th century in a gold ore from the mines in [[Zlatna|Kleinschlatten]] (today Zlatna), near today's city of [[Alba Iulia]], Romania. This ore was known as "Faczebajer weißes blättriges Golderz" (white leafy gold ore from Faczebaja, German name of Facebánya, now Fața Băii in [[Alba County]]) or ''antimonalischer Goldkies'' (antimonic gold pyrite), and according to [[Anton von Rupprecht]], was ''Spießglaskönig'' (''argent molybdique''), containing native [[antimony]].<ref>{{cite journal|url =https://books.google.com/books?id=SXI_AAAAcAAJ&pg=PA70|last =Rupprecht, von|first = A.|title = Über den vermeintlichen siebenbürgischen natürlichen Spiessglaskönig|trans-title=On the supposedly native antimony of Transylvania|journal = Physikalische Arbeiten der Einträchtigen Freunde in Wien|volume = 1|issue =1 |date = 1783|pages = 70–74}}</ref> In 1782 [[Franz-Joseph Müller von Reichenstein]], who was then serving as the Austrian chief inspector of mines in Transylvania, concluded that the ore did not contain antimony but was [[bismuth sulfide]].<ref>{{cite journal|url = https://books.google.com/books?id=SXI_AAAAcAAJ&pg=PA57| last = Müller|first = F. J.|title = Über den vermeintlichen natürlichen Spiessglaskönig|journal = Physikalische Arbeiten der Einträchtigen Freunde in Wien|volume = 1|issue =1 |date = 1783|pages = 57–59}}</ref> The following year, he reported that this was erroneous and that the ore contained mostly gold and an unknown metal very similar to antimony. After a thorough investigation that lasted three years and included more than fifty tests, Müller determined the [[specific gravity]] of the mineral and noted that when heated, the new metal gives off a white smoke with a [[radish]]-like odor; that it imparts a red color to [[sulfuric acid]]; and that when this solution is diluted with water, it has a black precipitate. Nevertheless, he was not able to identify this metal and gave it the names ''aurum paradoxum'' (paradoxical gold) and ''metallum problematicum'' (problem metal), because it did not exhibit the properties predicted for antimony.<ref name="Reich">{{Cite journal|last = von Reichenstein|first = F. J. M.|date = 1783|title = Versuche mit dem in der Grube Mariahilf in dem Gebirge Fazebay bey Zalathna vorkommenden vermeinten gediegenen Spiesglaskönig|trans-title=Experiments with supposedly native antimony occurring in the Mariahilf mine in the Fazeby mountains near Zalathna|journal = Physikalische Arbeiten der Einträchtigen Freunde in Wien|issue = 1.Quartal|volume = 1783|pages = 63–69|url=https://books.google.com/books?id=SXI_AAAAcAAJ&pg=PA63}}</ref><ref name="ChiuZ" /><ref name="Weeks" />

In 1789, a Hungarian scientist, [[Pál Kitaibel]], discovered the element independently in an ore from [[Deutsch-Pilsen]] that had been regarded as argentiferous [[molybdenite]], but later he gave the credit to Müller. In 1798, it was named by [[Martin Heinrich Klaproth]], who had earlier isolated it from the mineral [[calaverite]].<ref>Klaproth (1798) [https://books.google.com/books?id=8ws_AAAAcAAJ&pg=PA95 "Ueber die siebenbürgischen Golderze, und das in selbigen enthaltene neue Metall"] (On the Transylvanian gold ore, and the new metal contained in it), ''Chemische Annalen für die Freunde der Naturlehre, Arzneygelahrtheit, Haushaltungskunst und Manufacturen'' (Chemical Annals for the Friends of Science, Medicine, Economics, and Manufacturing), '''1''' : 91–104. From [https://books.google.com/books?id=8ws_AAAAcAAJ&pg=PA100-IA4 page 100:] " ''… ; und welchem ich hiermit den, von der alten Muttererde entlehnten, Namen ''Tellurium'' beylege.''" ( … ; and to which I hereby bestow the name ''tellurium'', derived from the old Mother of the Earth.)
* {{cite journal |last1=Klaproth |title=Analyse chimique de la mine de Tellure de Transylvanie |journal=Mémoires de l'Académie royale des sciences et belles-lettres (Berlin). § Classe de philosophie expérimentale |date=1798 |pages=17–37 |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015073704093&seq=713 |trans-title=Chemical analysis of tellurium ores from Transylvania |language=French}}</ref><ref name="ChiuZ">{{Cite journal|journal = Chemie in unserer Zeit|volume = 36|issue = 5|pages = 334–337|date = 2002|title = Die spannende Entdeckungsgeschichte des Tellurs (1782–1798) Bedeutung und Komplexität von Elemententdeckungen|first = Ekkehard|last = Diemann|author2 = Müller, Achim|author3 = Barbu, Horia|doi = 10.1002/1521-3781(200210)36:5<334::AID-CIUZ334>3.0.CO;2-1}}</ref><ref name="Weeks">{{Cite journal|journal =Journal of Chemical Education|title = The discovery of the elements. VI. Tellurium and selenium |first = Mary Elvira |author-link=Mary Elvira Weeks|last =Weeks|date = 1932|pages = 474–485|doi =10.1021/ed009p474|volume =9|issue =3|bibcode = 1932JChEd...9..474W }}</ref><ref name="Weeks2">{{Cite journal|doi =10.1021/ed012p403|title =The discovery of tellurium|date =1935|last1 =Weeks|first1 =Mary Elvira|author-link1=Mary Elvira Weeks|journal =Journal of Chemical Education|volume =12|pages =403–408|bibcode = 1935JChEd..12..403W|issue =9 }}</ref>

In the early 1920s, [[Thomas Midgley Jr.]] found tellurium prevented [[engine knocking]] when added to fuel, but ruled it out due to the difficult-to-eradicate smell. Midgley went on to discover and popularize the use of [[tetraethyl lead]].<ref>{{cite book | last=Ramsden | first=Eileen | title=Chemistry extension file | publisher=Nelson Thornes | publication-place=Cheltenham | date=2002 | isbn=0-7487-6254-X | oclc=49239046 | page=34}}</ref>

The 1960s brought an increase in thermoelectric applications for tellurium (as [[bismuth telluride]]), and in [[Free machining steel|free-machining]] [[steel]] alloys, which became the dominant use. These applications were overtaken by the growing importance of CdTe in [[thin-film solar cell]]s in the 2000s.<ref name=usgs2/>