{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/64750"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/64750","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Chemistry and physical properties of axinites","abstract":"Electron microprobe analyses of 37 axinites substantiate the conclusions of Sanero and Gottardi (1968) as to the substitutional solid solution between octahedrally coordinated divalent cations Ca, Fe, and Mn. The analyses also suggest the substitution of Fe³⁺ for Al in the AlO₅(OH) octahedra for six axinites and the substitution of Al for Si in tetrahedral coordination for one specimen. The chemistry of the axinite group is best described by a new structural formula: [(Mn, Fe²⁺, Mg, Zn)(Ca<sub>2-x</sub>Mn<sub>x</sub>)(Al<sub>2-y</sub>Fe<sub>y</sub>³⁺)]₂<sup>VI</sup>(OH)₂[(B₂Si₈<sub>z</sub>Al<sub>z</sub>)<sup>IV</sup>O₃₀], where x < 1, y << 1, and z << 1. Pronounced layering approximately parallel to (lll), bands of B₂Si₈O₃₀ groups parallel to [011], and four types of octahedral chains influence indicatrix orientation, external morphology, and cleavage. Due to their proximity to octahedral chains, the b and c cell edges have high correlations with <r>, the mean radius of octahedral cations. Density and mean refractive index are shown to be highly correlated with the amount of transition metal oxides present for all axinites and 2Vα is highly correlated with Mg content for the non-zincian 2Ca-axinites. Reasonable estimates of composition can be obtained for the non-zincian 2Ca-axinites by using the following equations for the mole fraction of Mg, Fe, and Mn: Mg = -14.333 <R.I.>+ 0.012(2Vα) + 23.487 Fe= 71.937 <R.I.> - 11.810(p<sub>obs</sub>) - 81.890 Mn = -42.903 <R.I.> + 12.523(p<sub>obs</sub>) + 31.473.","abstract_html":"Electron microprobe analyses of 37 axinites substantiate the conclusions of Sanero and Gottardi (1968) as to the substitutional solid solution between octahedrally coordinated divalent cations Ca, Fe, and Mn. The analyses also suggest the substitution of Fe³⁺ for Al in the AlO₅(OH) octahedra for six axinites and the substitution of Al for Si in tetrahedral coordination for one specimen. The chemistry of the axinite group is best described by a new structural formula: [(Mn, Fe²⁺, Mg, Zn)(Ca&lt;sub&gt;2-x&lt;/sub&gt;Mn&lt;sub&gt;x&lt;/sub&gt;)(Al&lt;sub&gt;2-y&lt;/sub&gt;Fe&lt;sub&gt;y&lt;/sub&gt;³⁺)]₂&lt;sup&gt;VI&lt;/sup&gt;(OH)₂[(B₂Si₈&lt;sub&gt;z&lt;/sub&gt;Al&lt;sub&gt;z&lt;/sub&gt;)&lt;sup&gt;IV&lt;/sup&gt;O₃₀], where x &lt; 1, y &lt;&lt; 1, and z &lt;&lt; 1. Pronounced layering approximately parallel to (lll), bands of B₂Si₈O₃₀ groups parallel to [011], and four types of octahedral chains influence indicatrix orientation, external morphology, and cleavage. Due to their proximity to octahedral chains, the b and c cell edges have high correlations with &lt;r&gt;, the mean radius of octahedral cations. Density and mean refractive index are shown to be highly correlated with the amount of transition metal oxides present for all axinites and 2Vα is highly correlated with Mg content for the non-zincian 2Ca-axinites. Reasonable estimates of composition can be obtained for the non-zincian 2Ca-axinites by using the following equations for the mole fraction of Mg, Fe, and Mn: Mg = -14.333 &lt;R.I.&gt;+ 0.012(2Vα) + 23.487 Fe= 71.937 &lt;R.I.&gt; - 11.810(p&lt;sub&gt;obs&lt;/sub&gt;) - 81.890 Mn = -42.903 &lt;R.I.&gt; + 12.523(p&lt;sub&gt;obs&lt;/sub&gt;) + 31.473.","abstract_has_math":false,"creators":["Lumpkin, Gregory Randolph"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geological Sciences","degree_department":"Geological Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1978,"date_issued":"1978","date_published":"1978","updated_at":"2026-07-22T22:19:12Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/64750","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Geological Sciences"]},{"key":"dc:creator","label":"Author","values":["Lumpkin, Gregory Randolph"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-02-01T18:59:37Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-02-01T18:59:37Z"]},{"key":"dc:date.issued","label":"Date","values":["1978"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/64750"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Electron microprobe analyses of 37 axinites substantiate the conclusions of Sanero and Gottardi (1968) as to the substitutional solid solution between octahedrally coordinated divalent cations Ca, Fe, and Mn. The analyses also suggest the substitution of Fe³⁺ for Al in the AlO₅(OH) octahedra for six axinites and the substitution of Al for Si in tetrahedral coordination for one specimen. The chemistry of the axinite group is best described by a new structural formula: [(Mn, Fe²⁺, Mg, Zn)(Ca<sub>2-x</sub>Mn<sub>x</sub>)(Al<sub>2-y</sub>Fe<sub>y</sub>³⁺)]₂<sup>VI</sup>(OH)₂[(B₂Si₈<sub>z</sub>Al<sub>z</sub>)<sup>IV</sup>O₃₀], where x < 1, y << 1, and z << 1. Pronounced layering approximately parallel to (lll), bands of B₂Si₈O₃₀ groups parallel to [011], and four types of octahedral chains influence indicatrix orientation, external morphology, and cleavage. Due to their proximity to octahedral chains, the b and c cell edges have high correlations with <r>, the mean radius of octahedral cations. Density and mean refractive index are shown to be highly correlated with the amount of transition metal oxides present for all axinites and 2Vα is highly correlated with Mg content for the non-zincian 2Ca-axinites. Reasonable estimates of composition can be obtained for the non-zincian 2Ca-axinites by using the following equations for the mole fraction of Mg, Fe, and Mn: Mg = -14.333 <R.I.>+ 0.012(2Vα) + 23.487 Fe= 71.937 <R.I.> - 11.810(p<sub>obs</sub>) - 81.890 Mn = -42.903 <R.I.> + 12.523(p<sub>obs</sub>) + 31.473."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Chemistry and physical properties of axinites"]}]}],"canonical_facts":{"dc:contributor.department":["Geological Sciences"],"dc:creator":["Lumpkin, Gregory Randolph"],"dc:date.accessioned":["2016-02-01T18:59:37Z"],"dc:date.available":["2016-02-01T18:59:37Z"],"dc:date.issued":["1978"],"dc:description.abstract":["Electron microprobe analyses of 37 axinites substantiate the conclusions of Sanero and Gottardi (1968) as to the substitutional solid solution between octahedrally coordinated divalent cations Ca, Fe, and Mn. The analyses also suggest the substitution of Fe³⁺ for Al in the AlO₅(OH) octahedra for six axinites and the substitution of Al for Si in tetrahedral coordination for one specimen. The chemistry of the axinite group is best described by a new structural formula: [(Mn, Fe²⁺, Mg, Zn)(Ca<sub>2-x</sub>Mn<sub>x</sub>)(Al<sub>2-y</sub>Fe<sub>y</sub>³⁺)]₂<sup>VI</sup>(OH)₂[(B₂Si₈<sub>z</sub>Al<sub>z</sub>)<sup>IV</sup>O₃₀], where x < 1, y << 1, and z << 1. Pronounced layering approximately parallel to (lll), bands of B₂Si₈O₃₀ groups parallel to [011], and four types of octahedral chains influence indicatrix orientation, external morphology, and cleavage. Due to their proximity to octahedral chains, the b and c cell edges have high correlations with <r>, the mean radius of octahedral cations. Density and mean refractive index are shown to be highly correlated with the amount of transition metal oxides present for all axinites and 2Vα is highly correlated with Mg content for the non-zincian 2Ca-axinites. Reasonable estimates of composition can be obtained for the non-zincian 2Ca-axinites by using the following equations for the mole fraction of Mg, Fe, and Mn: Mg = -14.333 <R.I.>+ 0.012(2Vα) + 23.487 Fe= 71.937 <R.I.> - 11.810(p<sub>obs</sub>) - 81.890 Mn = -42.903 <R.I.> + 12.523(p<sub>obs</sub>) + 31.473."],"dc:description.degree":["Master of Science"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/64750"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Chemistry and physical properties of axinites"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Geological Sciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:12Z"}