Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure

<p>A second occurrence of bobtraillite is described from the Gejiu nepheline syenite, southwestern China. The extremely rare and complex boron-bearing zirconium silicate is associated with albite, orthoclase, jadeite, fluorite, andradite, titanite, as well as other REE and zirconium-bearing mi...

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Main Authors: Y. Wang, F. Nestola, Z. Hou, X. Gu, G. Dong, Z. Yang, G. Fan, Z. Xiao, K. Qu
Format: Article
Language:English
Published: Copernicus Publications 2023-01-01
Series:European Journal of Mineralogy
Online Access:https://ejm.copernicus.org/articles/35/65/2023/ejm-35-65-2023.pdf
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author Y. Wang
Y. Wang
F. Nestola
Z. Hou
X. Gu
G. Dong
Z. Yang
G. Fan
Z. Xiao
K. Qu
K. Qu
author_facet Y. Wang
Y. Wang
F. Nestola
Z. Hou
X. Gu
G. Dong
Z. Yang
G. Fan
Z. Xiao
K. Qu
K. Qu
author_sort Y. Wang
collection DOAJ
description <p>A second occurrence of bobtraillite is described from the Gejiu nepheline syenite, southwestern China. The extremely rare and complex boron-bearing zirconium silicate is associated with albite, orthoclase, jadeite, fluorite, andradite, titanite, as well as other REE and zirconium-bearing minerals, catapleiite, moxuanxueite, låvenite, eudialyte, britholite-(Ce), and calcioancylite-(La). The EMP and LA-ICP-MS analyses of the studied material give an empirical formula: (Na<span class="inline-formula"><sub>9.70</sub></span>Li<span class="inline-formula"><sub>0.42</sub></span>K<span class="inline-formula"><sub>0.08</sub>□<sub>1.80</sub></span>)<span class="inline-formula"><sub>Σ12.00</sub></span>(Sr<span class="inline-formula"><sub>10.61</sub></span>Ca<span class="inline-formula"><sub>1.14</sub></span>Fe<span class="inline-formula"><sub>0.07</sub>□<sub>0.18</sub></span>)<span class="inline-formula"><sub>Σ12.00</sub></span>(Zr<span class="inline-formula"><sub>12.87</sub></span>Ti<span class="inline-formula"><sub>0.53</sub></span>Nb<span class="inline-formula"><sub>0.31</sub></span>REE<span class="inline-formula"><sub>0.08</sub></span>Y<span class="inline-formula"><sub>0.06</sub></span>U<span class="inline-formula"><sub>0.02</sub></span>Th<span class="inline-formula"><sub>0.01</sub>□<sub>0.12</sub></span>)<span class="inline-formula"><sub>Σ14.00</sub></span>(Si<span class="inline-formula"><sub>42.41</sub></span>B<span class="inline-formula"><sub>5.59</sub></span>Al<span class="inline-formula"><sub>0.02</sub></span>)<span class="inline-formula"><sub>Σ48.02</sub></span>O<span class="inline-formula"><sub>132</sub></span>(OH)<span class="inline-formula"><sub>12</sub></span> <span class="inline-formula"><span class="Radical">⚫</span></span> 12H<span class="inline-formula"><sub>2</sub></span>O. Bobtraillite is trigonal, with space group <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mover accent="true"><mn mathvariant="normal">3</mn><mo mathvariant="normal">¯</mo></mover><mi>c</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="3c1302eaea2aa69cf43c4367df4d285f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-35-65-2023-ie00001.svg" width="23pt" height="12pt" src="ejm-35-65-2023-ie00001.png"/></svg:svg></span></span>1, <span class="inline-formula"><i>a</i>=19.6977(6)</span>, <span class="inline-formula"><i>c</i>=9.9770(3)</span> Å, <span class="inline-formula"><i>V</i>=3352.4(2)</span> Å<span class="inline-formula"><sup>3</sup></span>, <span class="inline-formula"><i>Z</i>=1</span>. Single-crystal structure refinement revealed that all sodium occupies the Na(1) and Na(2) sites; the site occupancy of these two positions is 0.835(18) and 0.15(2), respectively, suggesting that Na(1) site is Na dominant, while Na(2) is a vacancy-dominant site. The [8]-coordinated site has been assigned to Sr and Ca, with free occupancy factors, 0.874(10) and 0.126(10), respectively. These new data indicate that the ideal formula of bobtraillite could be written as (Na,<span class="inline-formula">□</span>)<span class="inline-formula"><sub>12</sub></span>(<span class="inline-formula">□</span>,Na)<span class="inline-formula"><sub>12</sub></span>Sr<span class="inline-formula"><sub>12</sub></span>Zr<span class="inline-formula"><sub>14</sub></span>(Si<span class="inline-formula"><sub>3</sub></span>O<span class="inline-formula"><sub>9</sub></span>)<span class="inline-formula"><sub>10</sub></span>[Si<span class="inline-formula"><sub>2</sub></span>BO<span class="inline-formula"><sub>7</sub></span>(OH)<span class="inline-formula"><sub>2</sub></span>]<span class="inline-formula"><sub>6</sub></span> <span class="inline-formula"><span class="Radical">⚫</span></span> 12H<span class="inline-formula"><sub>2</sub></span>O.</p>
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spelling doaj.art-3d6c4a6a14fb4acd9f5591d40b59647c2023-01-31T09:54:05ZengCopernicus PublicationsEuropean Journal of Mineralogy0935-12211617-40112023-01-0135657410.5194/ejm-35-65-2023Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structureY. Wang0Y. Wang1F. Nestola2Z. Hou3X. Gu4G. Dong5Z. Yang6G. Fan7Z. Xiao8K. Qu9K. Qu10School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, ChinaDepartment of Geosciences, University of Padova, Padua, 35131, ItalyDepartment of Geosciences, University of Padova, Padua, 35131, ItalySchool of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, ChinaSchool of Geosciences and Info-Physics, Central South University, Changsha, 410083, ChinaSchool of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, ChinaInstitute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, ChinaInstitute of Science and Technology Information, Beijing Research Institute of Uranium Geology, Beijing, 100029, ChinaTianjin Center, China Geological Survey, Tianjin, 300171, ChinaTianjin Center, China Geological Survey, Tianjin, 300171, ChinaSchool of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China<p>A second occurrence of bobtraillite is described from the Gejiu nepheline syenite, southwestern China. The extremely rare and complex boron-bearing zirconium silicate is associated with albite, orthoclase, jadeite, fluorite, andradite, titanite, as well as other REE and zirconium-bearing minerals, catapleiite, moxuanxueite, låvenite, eudialyte, britholite-(Ce), and calcioancylite-(La). The EMP and LA-ICP-MS analyses of the studied material give an empirical formula: (Na<span class="inline-formula"><sub>9.70</sub></span>Li<span class="inline-formula"><sub>0.42</sub></span>K<span class="inline-formula"><sub>0.08</sub>□<sub>1.80</sub></span>)<span class="inline-formula"><sub>Σ12.00</sub></span>(Sr<span class="inline-formula"><sub>10.61</sub></span>Ca<span class="inline-formula"><sub>1.14</sub></span>Fe<span class="inline-formula"><sub>0.07</sub>□<sub>0.18</sub></span>)<span class="inline-formula"><sub>Σ12.00</sub></span>(Zr<span class="inline-formula"><sub>12.87</sub></span>Ti<span class="inline-formula"><sub>0.53</sub></span>Nb<span class="inline-formula"><sub>0.31</sub></span>REE<span class="inline-formula"><sub>0.08</sub></span>Y<span class="inline-formula"><sub>0.06</sub></span>U<span class="inline-formula"><sub>0.02</sub></span>Th<span class="inline-formula"><sub>0.01</sub>□<sub>0.12</sub></span>)<span class="inline-formula"><sub>Σ14.00</sub></span>(Si<span class="inline-formula"><sub>42.41</sub></span>B<span class="inline-formula"><sub>5.59</sub></span>Al<span class="inline-formula"><sub>0.02</sub></span>)<span class="inline-formula"><sub>Σ48.02</sub></span>O<span class="inline-formula"><sub>132</sub></span>(OH)<span class="inline-formula"><sub>12</sub></span> <span class="inline-formula"><span class="Radical">⚫</span></span> 12H<span class="inline-formula"><sub>2</sub></span>O. Bobtraillite is trigonal, with space group <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>P</mi><mover accent="true"><mn mathvariant="normal">3</mn><mo mathvariant="normal">¯</mo></mover><mi>c</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="3c1302eaea2aa69cf43c4367df4d285f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-35-65-2023-ie00001.svg" width="23pt" height="12pt" src="ejm-35-65-2023-ie00001.png"/></svg:svg></span></span>1, <span class="inline-formula"><i>a</i>=19.6977(6)</span>, <span class="inline-formula"><i>c</i>=9.9770(3)</span> Å, <span class="inline-formula"><i>V</i>=3352.4(2)</span> Å<span class="inline-formula"><sup>3</sup></span>, <span class="inline-formula"><i>Z</i>=1</span>. Single-crystal structure refinement revealed that all sodium occupies the Na(1) and Na(2) sites; the site occupancy of these two positions is 0.835(18) and 0.15(2), respectively, suggesting that Na(1) site is Na dominant, while Na(2) is a vacancy-dominant site. The [8]-coordinated site has been assigned to Sr and Ca, with free occupancy factors, 0.874(10) and 0.126(10), respectively. These new data indicate that the ideal formula of bobtraillite could be written as (Na,<span class="inline-formula">□</span>)<span class="inline-formula"><sub>12</sub></span>(<span class="inline-formula">□</span>,Na)<span class="inline-formula"><sub>12</sub></span>Sr<span class="inline-formula"><sub>12</sub></span>Zr<span class="inline-formula"><sub>14</sub></span>(Si<span class="inline-formula"><sub>3</sub></span>O<span class="inline-formula"><sub>9</sub></span>)<span class="inline-formula"><sub>10</sub></span>[Si<span class="inline-formula"><sub>2</sub></span>BO<span class="inline-formula"><sub>7</sub></span>(OH)<span class="inline-formula"><sub>2</sub></span>]<span class="inline-formula"><sub>6</sub></span> <span class="inline-formula"><span class="Radical">⚫</span></span> 12H<span class="inline-formula"><sub>2</sub></span>O.</p>https://ejm.copernicus.org/articles/35/65/2023/ejm-35-65-2023.pdf
spellingShingle Y. Wang
Y. Wang
F. Nestola
Z. Hou
X. Gu
G. Dong
Z. Yang
G. Fan
Z. Xiao
K. Qu
K. Qu
Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
European Journal of Mineralogy
title Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
title_full Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
title_fullStr Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
title_full_unstemmed Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
title_short Bobtraillite from Gejiu hyperagpaitic nepheline syenite, southwestern China: new occurrence and crystal structure
title_sort bobtraillite from gejiu hyperagpaitic nepheline syenite southwestern china new occurrence and crystal structure
url https://ejm.copernicus.org/articles/35/65/2023/ejm-35-65-2023.pdf
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