Enigmatic diamonds from the Tolbachik volcano, Kamchatka
Approximately 700 diamond crystals were identified in volcanic (mainly pyroclastic) rocks of the Tolbachik volcano, Kamchatka, Russia. They were studied with the use of SIMS, scanning and transmission electron microscopy, and utilization of electron energy loss spectroscopy and electron diffraction....
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5001701 2023-05-15T16:59:03+02:00 Enigmatic diamonds from the Tolbachik volcano, Kamchatka Galimov, E. Kaminsky, F. Shilobreeva, S. Sevastyanov, V. Voropaev, S. Khachatryan, G. Wirth, R. Schreiber, A. Saraykin, V. Karpov, G. Anikin, L. 2020 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5001701 unknown info:eu-repo/semantics/altIdentifier/doi/10.2138/am-2020-7119 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5001701 American Mineralogist info:eu-repo/semantics/article 2020 ftgfzpotsdam https://doi.org/10.2138/am-2020-7119 2022-09-14T05:57:31Z Approximately 700 diamond crystals were identified in volcanic (mainly pyroclastic) rocks of the Tolbachik volcano, Kamchatka, Russia. They were studied with the use of SIMS, scanning and transmission electron microscopy, and utilization of electron energy loss spectroscopy and electron diffraction. Diamonds have cube-octahedral shape and extremely homogeneous internal structure. Two groups of impurity elements are distinguished by their distribution within the diamond. First group, N and H, the most common structural impurities in diamond, are distributed homogeneously. All other elements observed (Cl, F, O, S, Si, Al, Ca, and K) form local concentrations, implying the existence of inclusions, causing high concentrations of these elements. Most elements have concentrations 3–4 orders of magnitude less than chondritic values. Besides N and H, Si, F, Cl, and Na are relatively enriched because they are concentrated in micro- and nanoinclusions in diamond. Mineral inclusions in the studied diamonds are 70–450 nm in size, round- or oval-shaped. They are represented by two mineral groups: Mn-Ni alloys and silicides, with a wide range of concentrations for each group. Alloys vary in stoichiometry from MnNi to Mn2Ni, with a minor admixture of Si from 0 to 5.20–5.60 at%. Silicides, usually coexisting with alloys, vary in composition from (Mn,Ni)4Si to (Mn,Ni)5Si2 and Mn5Si2, and further to MnSi, forming pure Mn-silicides. Mineral inclusions have nanometer-sized bubbles that contain a fluid or a gas phase (F and O). Carbon isotopic compositions in diamonds vary from –21 to –29‰ δ13CVPDB (avg. = –25.4). Nitrogen isotopic compositions in diamond from Tolbachik volcano are from –2.32 to –2.58‰ δ15NAir. Geological, geochemical, and mineralogical data confirm the natural origin of studied Tolbachik diamonds from volcanic gases during the explosive stage of the eruption. Article in Journal/Newspaper Kamchatka GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Tolbachik ENVELOPE(159.960,159.960,55.537,55.537) American Mineralogist 105 4 498 509 |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
unknown |
description |
Approximately 700 diamond crystals were identified in volcanic (mainly pyroclastic) rocks of the Tolbachik volcano, Kamchatka, Russia. They were studied with the use of SIMS, scanning and transmission electron microscopy, and utilization of electron energy loss spectroscopy and electron diffraction. Diamonds have cube-octahedral shape and extremely homogeneous internal structure. Two groups of impurity elements are distinguished by their distribution within the diamond. First group, N and H, the most common structural impurities in diamond, are distributed homogeneously. All other elements observed (Cl, F, O, S, Si, Al, Ca, and K) form local concentrations, implying the existence of inclusions, causing high concentrations of these elements. Most elements have concentrations 3–4 orders of magnitude less than chondritic values. Besides N and H, Si, F, Cl, and Na are relatively enriched because they are concentrated in micro- and nanoinclusions in diamond. Mineral inclusions in the studied diamonds are 70–450 nm in size, round- or oval-shaped. They are represented by two mineral groups: Mn-Ni alloys and silicides, with a wide range of concentrations for each group. Alloys vary in stoichiometry from MnNi to Mn2Ni, with a minor admixture of Si from 0 to 5.20–5.60 at%. Silicides, usually coexisting with alloys, vary in composition from (Mn,Ni)4Si to (Mn,Ni)5Si2 and Mn5Si2, and further to MnSi, forming pure Mn-silicides. Mineral inclusions have nanometer-sized bubbles that contain a fluid or a gas phase (F and O). Carbon isotopic compositions in diamonds vary from –21 to –29‰ δ13CVPDB (avg. = –25.4). Nitrogen isotopic compositions in diamond from Tolbachik volcano are from –2.32 to –2.58‰ δ15NAir. Geological, geochemical, and mineralogical data confirm the natural origin of studied Tolbachik diamonds from volcanic gases during the explosive stage of the eruption. |
format |
Article in Journal/Newspaper |
author |
Galimov, E. Kaminsky, F. Shilobreeva, S. Sevastyanov, V. Voropaev, S. Khachatryan, G. Wirth, R. Schreiber, A. Saraykin, V. Karpov, G. Anikin, L. |
spellingShingle |
Galimov, E. Kaminsky, F. Shilobreeva, S. Sevastyanov, V. Voropaev, S. Khachatryan, G. Wirth, R. Schreiber, A. Saraykin, V. Karpov, G. Anikin, L. Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
author_facet |
Galimov, E. Kaminsky, F. Shilobreeva, S. Sevastyanov, V. Voropaev, S. Khachatryan, G. Wirth, R. Schreiber, A. Saraykin, V. Karpov, G. Anikin, L. |
author_sort |
Galimov, E. |
title |
Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
title_short |
Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
title_full |
Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
title_fullStr |
Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
title_full_unstemmed |
Enigmatic diamonds from the Tolbachik volcano, Kamchatka |
title_sort |
enigmatic diamonds from the tolbachik volcano, kamchatka |
publishDate |
2020 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5001701 |
long_lat |
ENVELOPE(159.960,159.960,55.537,55.537) |
geographic |
Tolbachik |
geographic_facet |
Tolbachik |
genre |
Kamchatka |
genre_facet |
Kamchatka |
op_source |
American Mineralogist |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.2138/am-2020-7119 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5001701 |
op_doi |
https://doi.org/10.2138/am-2020-7119 |
container_title |
American Mineralogist |
container_volume |
105 |
container_issue |
4 |
container_start_page |
498 |
op_container_end_page |
509 |
_version_ |
1766051224388370432 |