<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>J. J. Papike</dc:contributor>
  <dc:creator>G. R. Himmelberg</dc:creator>
  <dc:date>1969</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Four pairs of associated calcic and sodic amphiboles from blueschist facies metamorphic rocks were analyzed with the electron microprobe and studied by single-crystal X-ray diffraction techniques. Except for ranges in the ratios Mg/(Mg+Fe) and Fe&lt;/span&gt;&lt;sup&gt;3+&lt;/sup&gt;&lt;span&gt;/(Fe&lt;/span&gt;&lt;sup&gt;3+&lt;/sup&gt;&lt;span&gt;+Al+Ti), the sodic amphiboles are similar in chemical composition. The amount of calcium in the M(4)-site ranges only from 0·18 to 0·21 ion per formula unit. The calcic amphiboles, in addition to a range in Mg/(Mg+Fe), vary in Na/(Na+Ca) ratio (0·29–0·48). Three of the calcic amphiboles contain less than 1·5 calcium ions per formula unit, indicating a significant solid solution of sodic amphibole components in the calcic amphibole phase. The&amp;nbsp;&lt;/span&gt;&lt;i&gt;a&lt;/i&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;i&gt;b&lt;/i&gt;&lt;span&gt;&amp;nbsp;unit-cell parameters of the calcic amphiboles decrease with increased content of the sodic component.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1093/petrology/10.1.102</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Oxford University Press</dc:publisher>
  <dc:title>Coexisting amphiboles from blueschist facies metamorphic rocks</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>