Editing Diamond (section)

=== In space ===
{{Main|Extraterrestrial diamonds}}
Although diamonds on [[Earth]] are rare, they are very common in space. In [[meteorite]]s, about three percent of the carbon is in the form of [[nanodiamond]]s, having diameters of a few nanometers. Sufficiently small diamonds can form in the cold of space because their lower [[surface energy]] makes them more stable than graphite. The isotopic signatures of some nanodiamonds indicate they were formed outside the Solar System in stars.<ref>{{cite journal| vauthors = Tielens AG |title=The molecular universe|journal=Reviews of Modern Physics|date=July 12, 2013|volume=85|issue=3|pages=1021–1081|doi=10.1103/RevModPhys.85.1021|bibcode=2013RvMP...85.1021T}}</ref>

High pressure experiments predict that large quantities of diamonds condense from [[methane]] into a "diamond rain" on the ice giant planets [[Uranus]] and [[Neptune]].<ref>{{cite journal | vauthors = Kerr RA | title = Neptune may crush methane into diamonds | journal = Science | volume = 286 | issue = 5437 | pages = 25 | date = October 1999 | pmid = 10532884 | doi = 10.1126/science.286.5437.25a | s2cid = 42814647 }}</ref><ref>{{cite journal| vauthors = Scandolo S, Jeanloz R |author-link2=Raymond Jeanloz |title=The Centers of Planets: In laboratories and computers, shocked and squeezed matter turns metallic, coughs up diamonds and reveals Earth's white-hot center|journal=American Scientist|date=November–December 2003|volume=91|issue=6|pages=516–525|jstor=27858301|bibcode=2003AmSci..91..516S|doi=10.1511/2003.38.905|s2cid=120975663 }}</ref><ref>{{cite news |vauthors=Kaplan S |title=It rains solid diamonds on Uranus and Neptune |url=https://www.washingtonpost.com/news/speaking-of-science/wp/2017/08/25/it-rains-solid-diamonds-on-uranus-and-neptune/ |access-date=October 16, 2017 |newspaper=[[The Washington Post]] |date=August 25, 2017 |archive-date=August 27, 2017 |archive-url=https://web.archive.org/web/20170827011901/https://www.washingtonpost.com/news/speaking-of-science/wp/2017/08/25/it-rains-solid-diamonds-on-uranus-and-neptune/ |url-status=live }}</ref> Some extrasolar planets may be almost entirely composed of diamond.<ref>{{cite news|last1=Max Planck Institute for Radio Astronomy|title=A planet made of diamond|url=http://www.astronomy.com/news/2011/08/a-planet-made-of-diamond|access-date=September 25, 2017|work=Astronomy magazine|date=August 25, 2011|archive-date=May 14, 2023|archive-url=https://web.archive.org/web/20230514174530/https://astronomy.com/news/2011/08/a-planet-made-of-diamond|url-status=live}}</ref>

Diamonds may exist in carbon-rich stars, particularly [[white dwarf]]s. One theory for the origin of [[carbonado]], the toughest form of diamond, is that it originated in a white dwarf or [[supernova]].<ref>{{cite journal | vauthors = Heaney PJ, de Vicenzi EP |title=Strange Diamonds: the Mysterious Origins of Carbonado and Framesite |journal=Elements |volume=1 |pages=85–89 |year=2005 |doi=10.2113/gselements.1.2.85 |issue=2|bibcode=2005Eleme...1...85H }}</ref><ref>{{cite journal | vauthors = Shumilova T, Tkachev S, Isaenko S, Shevchuk S, Rappenglück M, Kazakov V |title=A "diamond-like star" in the lab. Diamond-like glass |journal=Carbon |date=April 2016 |volume=100 |pages=703–709 |doi=10.1016/j.carbon.2016.01.068|doi-access=free |bibcode=2016Carbo.100..703S }}</ref> Diamonds formed in stars may have been the first minerals.<ref>{{cite news |vauthors=Wei-Haas M |title=Life and Rocks May Have Co-Evolved on Earth |url=http://www.smithsonianmag.com/science-nature/life-and-rocks-may-have-co-evolved-on-earth-180957807/ |access-date=September 26, 2017 |work=[[Smithsonian (magazine)|Smithsonian]] |language=en |archive-date=September 2, 2017 |archive-url=https://web.archive.org/web/20170902203717/http://www.smithsonianmag.com/science-nature/life-and-rocks-may-have-co-evolved-on-earth-180957807/ |url-status=live }}</ref>