Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Journal of Geology |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300304 |
Resumo: | Abstract Colorless quartz can develop a green color when submitted to gamma irradiation and its development is related to the presence of molecular water and hydroxyl groups in the quartz crystalline structure. In the present study, colorless quartz crystals hosted in geodes within rhyodacites of Serra Geral Group, Southern Brazil, were selected to test the potential development of green color. The samples were analyzed by infrared (IR) and thermogravimetric (TGA) techniques, in addition to the Amethyst Factor (fa) method. All samples showed an absorption bands in the IR, indicating possible development of a green or purple color, and fa analysis indicated the samples would develop a green color. All samples became colored after irradiation, presenting color zoning: from colorless to grayish-green, and from grayish-green to slightly purplish. Some samples showed a greenish colored zone and developed an amethyst phantom crystal in its apical portion. In addition, a high content of water in samples that remained colorless after irradiation was detected. It is here interpreted that water concentration varied during quartz crystallization, enabling the development of the green color, and that the excess of water can inhibit the development of radiation-induced color in colorless natural quartz crystals. |
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Brazilian Journal of Geology |
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Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, BrazilQuartzgreen quartz, amethyst, infrared spectroscopyirradiationAbstract Colorless quartz can develop a green color when submitted to gamma irradiation and its development is related to the presence of molecular water and hydroxyl groups in the quartz crystalline structure. In the present study, colorless quartz crystals hosted in geodes within rhyodacites of Serra Geral Group, Southern Brazil, were selected to test the potential development of green color. The samples were analyzed by infrared (IR) and thermogravimetric (TGA) techniques, in addition to the Amethyst Factor (fa) method. All samples showed an absorption bands in the IR, indicating possible development of a green or purple color, and fa analysis indicated the samples would develop a green color. All samples became colored after irradiation, presenting color zoning: from colorless to grayish-green, and from grayish-green to slightly purplish. Some samples showed a greenish colored zone and developed an amethyst phantom crystal in its apical portion. In addition, a high content of water in samples that remained colorless after irradiation was detected. It is here interpreted that water concentration varied during quartz crystallization, enabling the development of the green color, and that the excess of water can inhibit the development of radiation-induced color in colorless natural quartz crystals.Sociedade Brasileira de Geologia2020-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300304Brazilian Journal of Geology v.50 n.3 2020reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-488920202020190114info:eu-repo/semantics/openAccessTononi,Larissa LanesDuarte,Lauren da CunhaJuchem,Pedro LuizLameiras,Fernando SoaresSchnellrath,JurgenMenezes,Mauricio Thadeu Fenilli deeng2020-07-21T00:00:00Zoai:scielo:S2317-48892020000300304Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2020-07-21T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false |
dc.title.none.fl_str_mv |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
title |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
spellingShingle |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil Tononi,Larissa Lanes Quartz green quartz, amethyst, infrared spectroscopy irradiation |
title_short |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
title_full |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
title_fullStr |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
title_full_unstemmed |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
title_sort |
Potential development of green and purple colors in colorless natural quartz from geodes in rhyodacites, Serra Geral Group, Brazil |
author |
Tononi,Larissa Lanes |
author_facet |
Tononi,Larissa Lanes Duarte,Lauren da Cunha Juchem,Pedro Luiz Lameiras,Fernando Soares Schnellrath,Jurgen Menezes,Mauricio Thadeu Fenilli de |
author_role |
author |
author2 |
Duarte,Lauren da Cunha Juchem,Pedro Luiz Lameiras,Fernando Soares Schnellrath,Jurgen Menezes,Mauricio Thadeu Fenilli de |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Tononi,Larissa Lanes Duarte,Lauren da Cunha Juchem,Pedro Luiz Lameiras,Fernando Soares Schnellrath,Jurgen Menezes,Mauricio Thadeu Fenilli de |
dc.subject.por.fl_str_mv |
Quartz green quartz, amethyst, infrared spectroscopy irradiation |
topic |
Quartz green quartz, amethyst, infrared spectroscopy irradiation |
description |
Abstract Colorless quartz can develop a green color when submitted to gamma irradiation and its development is related to the presence of molecular water and hydroxyl groups in the quartz crystalline structure. In the present study, colorless quartz crystals hosted in geodes within rhyodacites of Serra Geral Group, Southern Brazil, were selected to test the potential development of green color. The samples were analyzed by infrared (IR) and thermogravimetric (TGA) techniques, in addition to the Amethyst Factor (fa) method. All samples showed an absorption bands in the IR, indicating possible development of a green or purple color, and fa analysis indicated the samples would develop a green color. All samples became colored after irradiation, presenting color zoning: from colorless to grayish-green, and from grayish-green to slightly purplish. Some samples showed a greenish colored zone and developed an amethyst phantom crystal in its apical portion. In addition, a high content of water in samples that remained colorless after irradiation was detected. It is here interpreted that water concentration varied during quartz crystallization, enabling the development of the green color, and that the excess of water can inhibit the development of radiation-induced color in colorless natural quartz crystals. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300304 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892020000300304 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2317-488920202020190114 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
dc.source.none.fl_str_mv |
Brazilian Journal of Geology v.50 n.3 2020 reponame:Brazilian Journal of Geology instname:Sociedade Brasileira de Geologia (SBGEO) instacron:SBGEO |
instname_str |
Sociedade Brasileira de Geologia (SBGEO) |
instacron_str |
SBGEO |
institution |
SBGEO |
reponame_str |
Brazilian Journal of Geology |
collection |
Brazilian Journal of Geology |
repository.name.fl_str_mv |
Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO) |
repository.mail.fl_str_mv |
sbgsede@sbgeo.org.br||claudio.riccomini@gmail.com |
_version_ |
1752122399379161088 |