Editing Group 9 element (section)

===Cobalt===
Cobalt compounds have been used for centuries to impart a rich blue color to [[glass]], [[ceramic glaze|glazes]], and [[Ceramics (art)|ceramics]]. Cobalt has been detected in Egyptian sculpture, Persian jewelry from the third millennium BC, in the ruins of [[Pompeii]], destroyed in 79&nbsp;AD, and in China, dating from the [[Tang dynasty]] (618–907&nbsp;AD) and the [[Ming dynasty]] (1368–1644&nbsp;AD).<ref>[https://www.britannica.com/EBchecked/topic/123235/cobalt-Co Cobalt], Encyclopædia Britannica Online.</ref>

Swedish chemist [[Georg Brandt]] (1694–1768) is credited with discovering cobalt <abbr>c.</abbr> 1735, showing it to be a previously unknown element, distinct from bismuth and other traditional metals. Brandt called it a new "semi-metal".<ref>Georg Brandt first showed cobalt to be a new metal in: G. Brandt (1735) "Dissertatio de semimetallis" (Dissertation on semi-metals), ''Acta Literaria et Scientiarum Sveciae'' (Journal of Swedish literature and sciences), vol. 4, pages 1–10.<br />See also: '''(1)''' G. Brandt (1746) "Rön och anmärkningar angäende en synnerlig färg—cobolt" (Observations and remarks concerning an extraordinary pigment—cobalt), ''Kongliga Svenska vetenskapsakademiens handlingar'' (Transactions of the Royal Swedish Academy of Science), vol. 7, pp. 119–130; '''(2)''' G. Brandt (1748) "Cobalti nova species examinata et descripta" (Cobalt, a new element examined and described), ''Acta Regiae Societatis Scientiarum Upsaliensis'' (Journal of the Royal Scientific Society of Uppsala), 1st series, vol. 3, pp. 33–41; '''(3)''' James L. Marshall and Virginia R. Marshall (Spring 2003) [https://web.archive.org/web/20100703175508/http://www.chem.unt.edu/Rediscovery/Riddarhyttan.pdf "Rediscovery of the Elements: Riddarhyttan, Sweden"]. ''The Hexagon'' (official journal of the [[Alpha Chi Sigma]] fraternity of chemists), vol. 94, no. 1, pages 3–8.</ref><ref name="Wang">{{cite journal|journal =Journal of the Minerals, Metals and Materials Society|volume = 58|issue = 10|date = 2006|doi = 10.1007/s11837-006-0201-y|pages = 47–50|title = Cobalt—Its recovery, recycling, and application|first = Shijie|last = Wang|bibcode = 2006JOM....58j..47W|s2cid = 137613322}}</ref> He showed that compounds of cobalt metal were the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Cobalt became the first metal to be discovered since the pre-historical period. All other known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers.