Editing Cinnabar (section)

=== Properties ===
Cinnabar is generally found in a massive, granular, or earthy form and is bright scarlet to brick-red in color, though it occasionally occurs in crystals with a nonmetallic [[adamantine lustre|adamantine luster]].<ref name="today">{{cite journal | journal = Geology Today | volume = 18 | issue = 5 | pages = 195–199 | title = Minerals Explained 37: Cinnabar | first = R. J. | last = King | doi = 10.1046/j.0266-6979.2003.00366.x | year = 2002 | s2cid = 247674748 }}</ref><ref>{{cite book|last1=Klein |first1=Cornelis |first2=Cornelius S. Jr |last2=Hurlbut |title=Manual of Mineralogy |url=https://archive.org/details/manualofmineralo00klei |url-access=registration |publisher=Wiley |edition=20th |date=1985 |page=[https://archive.org/details/manualofmineralo00klei/page/281 281] |isbn=0-471-80580-7}}</ref> It resembles [[quartz]] in its symmetry. It exhibits [[birefringence]], and it has the second-highest [[refractive index]] of any [[mineral]].<ref name=gemsoc-ri-dr>{{Cite web|url=https://www.gemsociety.org/article/table-refractive-index-double-refraction-gems/|title=Table of Refractive Indices and Double Refraction of Selected Gems - IGS|website=International Gem Society|language=en|access-date=2020-01-22}}</ref> Its mean refractive index is 3.08 ([[sodium light]] wavelengths),<ref name=schumann>{{cite book | last = Schumann | first = W. | title = Gemstones of the World | location = New York, NY | publisher = Sterling | year = 1997 | isbn = 0-8069-9461-4 | url-access = registration | url = https://archive.org/details/gemstonesofworld00schu }}{{page needed|date=July 2015}}</ref> versus the indices for [[diamond]] and the non-mineral [[Gallium arsenide|gallium(III) arsenide]] (GaAs), which are 2.42 and 3.93, respectively. The hardness of cinnabar is 2.0–2.5 on the [[Mohs scale]], and its [[specific gravity]] 8.1.<ref name=Webmin/>