Editing Lapis lazuli (section)

===Color===

[[File:Lapis-Lazuli microscope x240.jpg|thumb|upright|Lapis lazuli seen through a microscope (x240 magnification)]]

The intense blue color is due to the presence of the [[trisulfur]] [[radical anion]] ({{chem|S|3|•−}}) in the crystal.<ref>{{cite journal | last1 = Boros | first1 = E. | last2 = Earle | first2 = M. J. | last3 = Gilea | first3 = M. A. | last4 = Metlen | first4 = A. | last5 = Mudring | first5 = A.-V. | last6 = Rieger | first6 = F. | last7 = Robertson | first7 = A. J. | last8 = Seddon | first8 = K. R. | last9 = Tomaszowska | first9 = A. A. | last10 = Trusov | first10 = L. | last11 = Vyle | first11 = J. S. | year = 2010 | title = On the dissolution of non-metallic solid elements (sulfur, selenium, tellurium and phosphorus) in ionic liquids | url = https://works.bepress.com/anja_mudring/33/download/ | journal = Chem. Comm. | volume = 46 | issue = 5 | pages = 716–718 | doi = 10.1039/b910469k | pmid = 20087497 | access-date = 2018-04-20 | archive-date = 2017-09-22 | archive-url = https://web.archive.org/web/20170922042128/https://works.bepress.com/anja_mudring/33/download/ | url-status = live | url-access = subscription }}</ref> The presence of disulfur ({{chem|S|2|•−}}) and tetrasulfur ({{chem|S|4|•−}}) radicals can shift the color towards yellow or red, respectively.<ref>{{Cite journal |last1=Ganio |first1=Monica |last2=Pouyet |first2=Emeline S. |last3=Webb |first3=Samuel M. |last4=Patterson |first4=Catherine M. Schmidt |last5=Walton |first5=Marc S. |date=2018-03-01 |title=From lapis lazuli to ultramarine blue: investigating Cennino Cennini's recipe using sulfur K-edge XANES |journal=Pure and Applied Chemistry |language=en |volume=90 |issue=3 |pages=463–475 |doi=10.1515/pac-2017-0502 |s2cid=102593589 |issn=1365-3075 |doi-access=free }}</ref> These radical anions substitute for the chloride anions within the [[sodalite]] structure.<ref>{{Cite journal |last1=Reinen |first1=Dirk |last2=Lindner |first2=Gottlieb-Georg |date=1999-01-01 |title=The nature of the chalcogen colour centres in ultramarine-type solids |url=https://pubs.rsc.org/en/content/articlelanding/1999/cs/a704920j |journal=Chemical Society Reviews |language=en |volume=28 |issue=2 |pages=75–84 |doi=10.1039/A704920J |issn=1460-4744 |access-date=2022-06-16 |archive-date=2022-06-16 |archive-url=https://web.archive.org/web/20220616174412/https://pubs.rsc.org/en/content/articlelanding/1999/CS/a704920j |url-status=live |url-access=subscription }}</ref> The {{chem|S|3|•−}} radical anion exhibits a visible absorption band in the range 595–620&nbsp;nm with high molar absorptivity, leading to its bright blue color.<ref>{{Cite journal |last1=Chivers |first1=Tristram |last2=Elder |first2=Philip J. W. |date=2013-06-21 |title=Ubiquitous trisulfur radical anion: fundamentals and applications in materials science, electrochemistry, analytical chemistry and geochemistry |url=https://pubs.rsc.org/en/content/articlelanding/2013/cs/c3cs60119f |journal=Chemical Society Reviews |language=en |volume=42 |issue=14 |pages=5996–6005 |doi=10.1039/C3CS60119F |pmid=23628896 |issn=1460-4744 |access-date=2022-06-16 |archive-date=2022-06-16 |archive-url=https://web.archive.org/web/20220616174349/https://pubs.rsc.org/en/content/articlelanding/2013/cs/c3cs60119f |url-status=live |url-access=subscription }}</ref>