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<journal-meta>
<journal-id journal-id-type="archive">gsminmag</journal-id>
<journal-title>Mineralogical Magazine</journal-title>
<abbrev-journal-title abbrev-type="full">Mineralogical Magazine</abbrev-journal-title>
<issn pub-type="ppub">0026-461X</issn>
<publisher>
<publisher-name>Mineralogical Society</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.1180/minmag.1975.040.311.01</article-id>
<title-group>
<article-title>Xocomecatlite, Cu<sub>3</sub>TeO<sub>4</sub>(OH)<sub>4</sub>, and Tlalocite, Cu<sub>10</sub>Zn<sub>6</sub>(TeO<sub>3</sub>)(TeO<sub>4</sub>)<sub>2</sub>Cl(OH)<sub>25</sub>&#x00B7;27H<sub>2</sub>O, Two New Minerals from Moctezuma, Sonora, Mexico</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Williams</surname>
<given-names>S. A.</given-names>
</name>
<aff>Phelps Dodge Corporation, Douglas, Arizona, U.S.A.</aff></contrib></contrib-group>
<pub-date pub-type="ppub">
<month>9</month>
<year>1975</year>
</pub-date>
<volume>40</volume>
<issue>311</issue>
<fpage>221</fpage>
<lpage>226</lpage>
<history>
<date date-type="received">
<day>9</day>
<month>9</month>
<year>1974</year>
</date></history>
<copyright-statement>Copyright &#x00A9; 1975, The Mineralogical Society</copyright-statement>
<copyright-year>1975</copyright-year>
<abstract>
<title>Summary</title>
<p>Xocomecatlite and tlalocite were found at the Bambollita mine near Moctezuma, Sonora. Xocomecatlite is probably orthorhombic, and an indexed cell based on the powder data gave <italic>a</italic> 12&#x00B7;140 &#x00C5;, <italic>b</italic> 14&#x00B7;318, <italic>c</italic> 11&#x00B7;662. Based on this cell, the empirical contents are Cu<sub>35&#x00B7;6</sub> Zn<sub>1&#x00B7;7</sub> (TeO<sub>4</sub>)<sub>12&#x00B7;5</sub> (OH)<sub>51&#x00B7;6</sub> or Cu<sub>3</sub>TeO<sub>4</sub>(OH)<sub>4</sub>. Tellurate was found both microchemically and by spectrophotometry. Colour rich green (R.H.S. 132A) with pale streak, H = 4. Optically negative with &#x03B1; = 1&#x00B7;775, &#x03B2; = 1&#x00B7;900, &#x03B3; = 1&#x00B7;920. G = 4&#x00B7;65.</p>
<p>Tlalocite is optically orthorhombic but the cell could not be indexed; only powder data are presented. Chemical analysis showed both tellurite and tellurate and led to the formula Cu<sub>10</sub>Zn<sub>6</sub>(TeO<sub>3</sub>)(TeO<sub>3</sub>)(TeO)(TeO<sub>4</sub>)<sub>2</sub>Cl(OH)<sub>25</sub>&#x00B7;27H<sub>2</sub>O.</p>
<p>Colour pale blue (R.H.S. 121A) with a whitish streak; H = 1, gummy and sectile. G = 4&#x00B7;55.</p>
<p>Plotting stability fields for various Te species at 25 &#x00B0;C in terms of Eh and pH showed that <inline-formula><mml:math><mml:mrow><mml:msubsup><mml:mrow><mml:mi>TeO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>&#x2212;</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math></inline-formula>&#x00B7;aq can exist in nature over a wide pH range, but only under extreme conditions of oxidation.</p></abstract>
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