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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.1967.036.280.10</article-id>
<title-group>
<article-title><inline-formula><mml:math><mml:mrow><mml:mi>&#x0394;</mml:mi><mml:mn>2</mml:mn><mml:msub><mml:mo>&#x03B8;</mml:mo><mml:mrow><mml:mn>131</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mn>3</mml:mn><mml:mo>&#x00AF;</mml:mo></mml:mover><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> for Albites Crystallized in the Systems NaAlSi<sub>3</sub>O<sub>8</sub>-<italic>&#x03B2;</italic>-LiAlSi<sub>2</sub>O<sub>6</sub>-H<sub>2</sub>O and NaAlSi<sub>3</sub>O<sub>8</sub>-LiAlSiO<sub>4</sub>-H<sub>2</sub>O</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Edgar</surname>
<given-names>A. D.</given-names>
</name>
<aff>University of Western Ontario, London, Canada</aff></contrib>
<contrib contrib-type="author">
<name>
<surname>Piotrowski</surname>
<given-names>J. M.</given-names>
</name>
<aff>Southern Connecticut State College, New Haven, U.S.A.</aff></contrib></contrib-group>
<pub-date pub-type="ppub">
<month>12</month>
<year>1967</year>
</pub-date>
<volume>36</volume>
<issue>280</issue>
<fpage>578</fpage>
<lpage>582</lpage>
<history>
<date date-type="received">
<day>1</day>
<month>6</month>
<year>1967</year>
</date></history>
<copyright-statement>Copyright &#x00A9; 1967, The Mineralogical Society</copyright-statement>
<copyright-year>1967</copyright-year>
<abstract>
<title>Summary</title>
<p>Values of <inline-formula><mml:math><mml:mrow><mml:mi>&#x0394;</mml:mi><mml:mn>2</mml:mn><mml:msub><mml:mo>&#x03B8;</mml:mo><mml:mrow><mml:mn>131</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mn>3</mml:mn><mml:mo>&#x00AF;</mml:mo></mml:mover><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>Cu</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>K</mml:mi><mml:mo>&#x03B1;</mml:mo></mml:msub><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math></inline-formula>(Cu-<italic>K&#x03B1;</italic>) have been determined for albites crystallized in the system NaAlSi<sub>3</sub>O<sub>8</sub>-<italic>&#x03B2;</italic>-LiAlSi<sub>2</sub>O<sub>6</sub>-H<sub>2</sub>O at various pressures, temperatures, and times. These values are consistently higher than those reported by MacKenzie (1957) for pure synthetic albites crystallized under similar conditions. Data of the present study have been combined with that of Stewart (1960) for albites crystallized in the system NaAlSi<sub>3</sub>O<sub>8</sub>-LiAlSiO<sub>4</sub>-H<sub>2</sub>O and, when plotted against bulk Li<sub>2</sub>O content, show constant <inline-formula><mml:math><mml:mrow><mml:mi>&#x0394;</mml:mi><mml:mn>2</mml:mn><mml:msub><mml:mo>&#x03B8;</mml:mo><mml:mrow><mml:mn>131</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mn>3</mml:mn><mml:mo>&#x00AF;</mml:mo></mml:mover><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> values at approximately 1&#x00B7;0 wt. % Li<sub>2</sub>O. The addition of Li to albites has a much more pronounced effect on the <inline-formula><mml:math><mml:mrow><mml:mi>&#x0394;</mml:mi><mml:mn>2</mml:mn><mml:msub><mml:mo>&#x03B8;</mml:mo><mml:mrow><mml:mn>131</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mn>3</mml:mn><mml:mo>&#x00AF;</mml:mo></mml:mover><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> parameter than the addition of K or Ca. Albites from lithium-rich pegmatites have much lower <inline-formula><mml:math><mml:mrow><mml:mi>&#x0394;</mml:mi><mml:mn>2</mml:mn><mml:msub><mml:mo>&#x03B8;</mml:mo><mml:mrow><mml:mn>131</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mn>3</mml:mn><mml:mo>&#x00AF;</mml:mo></mml:mover><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> values and are similar to those of synthetic low albites. The differences in this parameter between the natural and synthetic specimens are believed to be caused by differences in the structures of the ceexisting lithium minerals in the natural and synthetic environments.</p></abstract>
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