Creedite

<h2 id="occurrence">Occurrence</h2>

<p>Creedite is a rare hydroxylhalide mineral. Creedite usually forms from the <a href="/facts/Oxidation/Pyd5RVcj">oxidation</a> of <a href="/facts/Fluorite/y2G7C8zk">fluorite</a> ore deposits. Creedite was named after the location where it was discovered in 1916 in the Colorado Fluorspar Co. Mine at Wagon Wheel Gap, located at Creede Quadrangle, <a href="/facts/Mineral_County,_Colorado/bdJtjquy">Mineral County, Colorado</a>.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>
</p><p>It was later found in other fluorite veins near <a href="/facts/Tonopah,_Nevada/oyQLFv8q">Tonopah</a>, <a href="/facts/Nye_County,_Nevada/BDeK44Sy">Nye County, Nevada</a>; in the Grand Reef mine, <a href="/facts/Graham_County,_Arizona/UoqFWw0p">Graham County, Arizona</a>; in the Darwin district, <a href="/facts/Inyo_County,_California/wFUl20UP">Inyo County, California</a>. It also occurs in the Potosi and other mines of <a href="/facts/Santa_Eulalia,_Chihuahua/GlLGRxCy">Santa Eulalia</a>, <a href="/facts/Chihuahua_(state)/FCeDVWL0">Chihuahua</a>, <a href="/facts/Mexico/IT5bwhdh">Mexico</a>. It is also found in <a href="/facts/La_Paz/mQAdR48Q">La Paz</a>, <a href="/facts/Bolivia/YNBoDKKR">Bolivia</a>; <a href="/facts/Pamir_Mountains/v5y6FB2f">Pamir Mountains</a>, <a href="/facts/Tajikistan/xLLXqHEJ">Tajikistan</a> and <a href="/facts/Dzhezkazgan/tRPuN5Hn">Dzhezkazgan</a>, <a href="/facts/Kazakhstan/Vfs8NI6e">Kazakhstan</a>.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>
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<h2 id="geologic-association">Geologic association</h2>

<p>Creedite typically occurs with low-grade <a href="/facts/Metamorphic_rock/JRp6dsCm">metamorphic rocks</a> on a fluorite – calcite – quartz matrix or on a sulfide-matrix with its oxidized products. Creedite most commonly found in the form of creedite – carbonate – <a href="/facts/Cyanotrichite/4H70PbIB">cyanotrichite</a> – woodwardite – spangolite – <a href="/facts/Kaolinite/N7D6K65q">kaolinite</a> association. The other less common creedite association is creedite – <a href="/facts/Limonite/KCPspvHH">limonite</a> – kaolinite – <a href="/facts/Hemimorphite/YDXNAQDb">hemimorphite</a> – <a href="/facts/Smithsonite/ffvou3Re">smithsonite</a> – <a href="/facts/Hydrozincite/aPe0MbK5">hydrozincite</a> – <a href="/facts/Aurichalcite/fgFWPWTE">aurichalcite</a>. Creedite also occurs in <a href="/facts/Skarn/CAPVrImS">skarn</a> formation which usually has association with <a href="/facts/Sulfide_mineral/f8rxJpCW">sulfides</a>, spangolite, <a href="/facts/Brochantite/Xoq6mMQ5">brochantite</a>, <a href="/facts/Linarite/VGFFnejo">linarite</a>, limonite, <a href="/facts/Cuprite/WdFFUXo2">cuprite</a>, <a href="/facts/Wad_(mineral)/Ym53uSw6">wad</a> and kaolinite. In general, creedite usually found as two to three millimeters radial <a href="/facts/Aggregate_(geology)/m7KAYtau">aggregates</a> and less commonly as a single prismatic crystals up to one millimeters long.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>
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<h2 id="structure">Structure</h2>
<p>Creedite structural composition study was conducted by utilizing 1390 Philips diffractometer with Fe – filtered CoK radiation (<a href="/facts/Wavelength/kcJU0ymz">λ</a>=1.79021<a href="/facts/Angstrom/T5mjdd97">Å</a>), 10–90° 2θ range, peak-height relative intensities. It was concluded that the creedite falls into monoclinic crystal system (2/m) that has space group of C2/c. It was also found that creedite has basal reflections of (2 0 0) and (4 0 0) that are enhanced due to preferred orientation which concur with Michael Fleischer's orientation.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
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<ul><li>Kiselva, I. A.; Ogorodova, L.P.; Mel'Chalkova, L.V.; Getmanskaya, T.I., Enthalpy of Formation of Creedite Ca3Al2F8.25(OH) (1.75)(SO4) Center dot 2H(2) O, Geochemistry International, pp. 1026–1030, OCT 2002.</li>
<li>Frau, F.; Rizzo, R.; Sabelli, C., Creedite from Sardinia, Italy: the first European Occurrence, Neues Jahrbuch für Mineralogie-Monashefte, pp. 495–504, NOV 1998.</li>
<li>Giuseppetti, G; Tadini, C., Structure Analysis and refinement of Bolivian Creedite, Ca3Al2F8(OH)2(SO4)*2(H2O), Neues Jahrbuch für Mineralogie-Monashefte, pp. 69–78, 1983.</li>
<li>Fleischer, M, Probable Identity of Belyankite With Creedite, U.S. Geological Survey, March 12, 1992.</li>
<li>K, Robert B., Creedite: Cresson Mine, Cripple Creek Teller County, Colorado. Rocks & Minerals, pp422–427, OCT 2008.</li>
<li>Foshag, W. F., (1932) Creedite from Nevada: Am. Mineral., 17, 75–77.</li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20051105220014/http://mineral.galleries.com/minerals/sulfates/creedite/creedite.htm">Mineral galleries</a></li></ul>

Wikimedia Commons has media related to Creedite.

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>http://www.mindat.org/min-1151.html Mindat <a href="http://www.mindat.org/min-1151.html" target="_blank">http://www.mindat.org/min-1151.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>http://rruff.geo.arizona.edu/doclib/hom/creedite.pdf Handbook of Mineralogy <a href="http://rruff.geo.arizona.edu/doclib/hom/creedite.pdf" target="_blank">http://rruff.geo.arizona.edu/doclib/hom/creedite.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Frau, F.; Rizzo, R.; Sabelli, C., Creedite from Sardinia, Italy: the first European Occurrence, Neues Jahrbuch für Mineralogie-Monashefte, pp.495–504, Nov. 1998. <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Giuseppetti, G; Tadini, C., Structure Analysis and refinement of Bolivian Creedite, Ca3Al2F8(OH)2(SO4)*2(H2O), Neues Jahrbuch für Mineralogie-Monashefte, pp.69–78, 1983 <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
</ol>

Creedite open-in-new

Creedite