Editing Cubic zirconia (section)

==Cubic zirconia vis-à-vis diamond==
Key features of cubic zirconia distinguish it from diamond:

[[File:Diamond face trigons scale.jpg|thumb|alt=A triangular facet of a crystal having triangular etch pits with the largest having a base length of about 0.2 mm|One face of an uncut octahedral diamond, showing trigons (of positive and negative relief) formed by natural [[Chemical milling|chemical etching]]]]

*Hardness: cubic zirconia has a rating of approximately 8 on [[Mohs scale of mineral hardness|Mohs hardness scale]] vs. a rating of 10 for diamond.<ref name="Mohs' Hardness of Abrasives"/> This may cause dull and rounded edges in CZ facets; the edges of diamond facets are much sharper by comparison. Furthermore, diamond rarely shows polish marks, and those which are apparent are oriented in different directions on adjoining facets, whereas CZ  shows marks in the same direction of the polish throughout.<ref name=":2" />
*The [[Specific gravity]]  or density of cubic zirconia is approximately 1.7 times that of diamond. This allows gemologists to differentiate the two substances by weight alone. This property can also be exploited, for example, by dropping the stones in a heavy liquid and comparing their relative rates of descent: diamond will sink more slowly than CZ.<ref name=":2" />
*[[Refractive index]]: cubic zirconia has a refractive index of 2.15–2.18, compared to a diamond's 2.42. This has led to the development of other immersion techniques for identification. In these methods, stones with refractive indices higher than that of the liquid used will have dark borders around the girdle and light facet edges whereas those with indices lower than the liquid will have light borders around the girdle and dark facet junctions.<ref name=":2" />
*[[dispersion (optics)|Dispersion]] is very high at 0.058–0.066, exceeding a diamond's 0.044.
*Cut: Cubic zirconia gemstones can be cut differently than diamonds: The facet edges can be rounded or "smooth".
*Color: only the rarest of diamonds are truly colorless, most having a tinge of yellow or brown to some extent. A cubic zirconia is often entirely colorless: equivalent to a perfect "D" on [[Diamond color|diamond's color]] grading scale. That said, desirable colors of cubic zirconia can be produced including near colorless, yellow, pink, purple, green, and even multicolored.
* Thermal conductivity: Cubic zirconia is a thermal insulator whereas diamond is the most powerful{{Citation needed|date=May 2024}} thermal conductor. This provides the basis for Wenckus’ canonical identification method, the industry standard.<ref name=":1" />

=== Effects on the diamond market ===
Cubic zirconia, as a [[diamond simulant]] and jewel competitor, can potentially reduce demand for [[conflict diamonds]], and impact the controversy surrounding the rarity and value of diamonds.<ref name=":3">{{Cite web|url=https://priceonomics.com/post/45768546804/diamonds-are-bullshit|title=Diamonds Are Bullshit|last=Dhar|first=Robin|date=19 March 2013|website=Priceonomics|access-date=10 May 2018|archive-date=11 April 2018|archive-url=https://web.archive.org/web/20180411194706/https://priceonomics.com/post/45768546804/diamonds-are-bullshit|url-status=dead}}</ref><ref name=":4">{{Cite web|url=https://www.forbes.com/sites/quora/2017/07/03/why-smart-people-buy-cubic-zirconia-engagement-rings/#70ca7ca7594f|title=Why Smart People Buy Cubic Zirconia Engagement Rings|last=Muller|first=Richard|date=3 July 2017|website=Forbes}}</ref>

Regarding value, the paradigm that diamonds are costly due to their rarity and visual beauty has been replaced by an artificial rarity<ref name=":3" /><ref name=":4" /> attributed to price-fixing practices of [[De Beers|De Beers Company]] which held a monopoly on the market from the 1870s to early 2000s.<ref name=":3" /><ref name=":5">{{Cite news|url=https://www.economist.com/node/2921462|title=The Diamond Cartel|last1=Johannesburg|last2=Windhoek|date=15 July 2004|newspaper=The Economist}}</ref> The company pleaded guilty to these charges in an Ohio court in 13 July 2004.<ref name=":5" /> However, while De Beers has less market power, the price of diamonds continues to increase due to the demand in emerging markets such as India and China.<ref name=":3" /> The emergence of artificial stones such as cubic zirconia with optic properties similar to diamonds, could be an alternative for jewelry buyers given their lower price and noncontroversial history.

An issue closely related to monopoly is the emergence of conflict diamonds. The [[Kimberley Process Certification Scheme|Kimberley Process]] (KP) was established to deter the illicit trade of diamonds that fund civil wars in [[Angola]] and [[Sierra Leone]].<ref name=":6">{{Cite magazine|url=https://time.com/blood-diamonds/|title=Blood Diamonds|last=Baker|first=Aryn|magazine=Time}}</ref> However, the KP is not as effective in decreasing the number of conflict diamonds reaching the European and American markets. Its definition does not include forced labor conditions or human right violations.<ref name=":6" /><ref>{{Cite web|url=https://www.brilliantearth.com/news/how-to-beat-the-smugglers-and-stop-blood-diamonds/|title=A Simple Way To Stop Blood Diamonds|last=K.|first=Greg|date=2 December 2014|website=Brilliant Earth}}</ref> A 2015 study from the [[Enough Project]], showed that groups in the [[Central African Republic]] have reaped between US$3&nbsp;million and US$6&nbsp;million annually from conflict diamonds.<ref name=":7">{{Cite web|url=http://www.scmp.com/news/world/article/2043572/why-illicit-diamond-trade-almost-gone-not-yet-forgotten|title=Why the illicit diamond trade is (almost) gone, but not yet forgotten|date=21 February 2017|website=SCMP}}</ref> UN reports show that more than US$24&nbsp;million in conflict diamonds have been smuggled since the establishment of the KP.<ref>{{Cite web|url=https://www.reuters.com/article/us-centralafrica-un-panel/gold-diamonds-fuelling-conflict-in-central-african-republic-u-n-panel-idUSKBN0IO21420141105|title=Gold, diamonds fuelling conflict in Central African Republic: U.N. panel|last=Flynn|first=Daniel|date=5 November 2014|website=Reuters}}</ref> Diamond simulants have become an alternative to boycott the funding of unethical practices.<ref name=":7" /> Terms such as “Eco-friendly Jewelry” define them as conflict free origin and environmentally sustainable.<ref>{{Cite web|url=https://www.brides.com/gallery/moissanite-engagement-rings|title=15 Moissanite Engagement Rings for the Eco-Friendly Bride|last=Hoffower|first=Hillary|date=21 April 2018|website=Brides}}</ref> However, concerns from mining countries such as the [[Democratic Republic of the Congo|Democratic Republic of Congo]] are that a boycott in purchases of diamonds would only worsen their economy. According to the Ministry of Mines in Congo, 10% of its population relies on the income from diamonds.<ref name=":6" /> Therefore, cubic zirconia are a short term alternative to reduce conflict but a long term solution would be to establish a more rigorous system of identifying the origin of these stones.