Editing Pyrochlore (section)

== Mineral ==
The general formula, {{chem2|A2B2O7}} (where A and B are metals), represent a family of phases isostructural to the mineral pyrochlore. Pyrochlores are an important class of materials in diverse technological applications such as luminescence, ionic conductivity, nuclear waste immobilization, high-temperature thermal barrier coatings, automobile [[exhaust gas]] control, catalysts, solid oxide fuel cell, ionic/electrical conductors etc.

The mineral is associated with the [[Metasomatism|metasomatic]] end stages of magmatic intrusions. Pyrochlore crystals are usually well-formed (euhedral), occurring usually as [[octahedron|octahedra]] of a yellowish or brownish color and [[resin]]ous luster. It is commonly [[metamict]] due to radiation damage from included radioactive elements.

Pyrochlore occurs in [[pegmatite]]s associated with [[nepheline syenite]]s and other alkalic rocks. It is also found in [[granite]] pegmatites and [[greisen]]s. It is characteristically found in [[carbonatite]]s. Associated minerals include [[zircon]], [[aegirine]], [[apatite]], [[perovskite]] and [[columbite]].<ref name="Handbook" />

=== History ===
It was first described in 1826 for an occurrence in Stavern (Fredriksvärn), [[Larvik]], Vestfold, Norway.<ref name="Mindat" />

=== Niobium mining ===
The three largest producers of niobium ore are mining pyrochlore deposits. The largest deposit in [[Brazil]] is the CBMM mine located south of [[Araxá]], Minas Gerais, followed by the deposit of the Catalão mine east of [[Catalão]], Goiás. The third largest deposit of niobium ore is Niobec mine west of [[Saint-Honoré, Quebec|Saint-Honoré]] near [[Chicoutimi]], Quebec.<ref name="tesla">{{cite web |last1=Kouptsidis |first1=J. |last2=Peters |first2=F. |last3=Proch |first3=D. |last4=Singer |first4=W. |title=Niob für TESLA |url=http://tesla.desy.de/new_pages/TESLA_Reports/2001/pdf_files/tesla2001-27.pdf |url-status=dead |archive-url=https://web.archive.org/web/20081217100548/http://tesla.desy.de/new_pages/TESLA_Reports/2001/pdf_files/tesla2001-27.pdf |archive-date=2008-12-17 |access-date=2008-09-02}}</ref>

Pyrochlore ore typically contains greater than 0.05% of naturally occurring radioactive [[uranium]] and [[thorium]].<ref>{{Cite journal |last1=Dias da Cunha |first1=K. |last2=Santos |first2=M. |last3=Zouain |first3=F. |last4=Carneiro |first4=L. |last5=Pitassi |first5=G. |last6=Lima |first6=C. |last7=Barros Leite |first7=C. V. |last8=Dália |first8=K. C. P. |date=May 8, 2009 |title=Dissolution Factors of Ta, Th, and U Oxides Present in Pyrochlore |journal=Water, Air, & Soil Pollution |volume=205 |issue=1–4 |pages=251–257 |doi=10.1007/s11270-009-0071-3 |issn=0049-6979 |s2cid=93478456}}</ref>

[[Lueshe]] in [[North Kivu]], Democratic Republic of Congo, has substantial deposits of pyrochlore.<ref>{{Cite web |title=Blood Minerals in the Kivu Provinces |url=https://www.globalpolicy.org/component/content/article/181/33658.html |website=www.globalpolicy.org}}</ref>