Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure
Megakalsilite, KAlSiO4, hexagonal, a 18.1111(8), c 8.4619(4) Å, V 2403.7(2) Å3, c:a = 0.4672, space group P63, Z = 24, R = 0.039 (for 3255 observed reflections collected with a four-circle X-ray diffractometer), is a new mineral species from Mount Koashva, Khibina alkaline massif, Kola Peninsula, Ru...
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ftunivpisairis:oai:arpi.unipi.it:11568/205759 2024-02-27T08:42:33+00:00 Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure KHOMYAKOV AP NECHELYUSTOV GN SOKOLOVA E BONACCORSI, ELENA MERLINO, STEFANO PASERO, MARCO Khomyakov, Ap Nechelyustov, Gn Sokolova, E Bonaccorsi, Elena Merlino, Stefano Pasero, Marco 2002 STAMPA http://hdl.handle.net/11568/205759 eng eng info:eu-repo/semantics/altIdentifier/wos/000177081400016 volume:40 firstpage:961 lastpage:970 numberofpages:10 journal:CANADIAN MINERALOGIST http://hdl.handle.net/11568/205759 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036614004 megakalsilite new mineral specie polymorph crystal structure Khibina Kola Peninsula info:eu-repo/semantics/article 2002 ftunivpisairis 2024-01-31T17:44:49Z Megakalsilite, KAlSiO4, hexagonal, a 18.1111(8), c 8.4619(4) Å, V 2403.7(2) Å3, c:a = 0.4672, space group P63, Z = 24, R = 0.039 (for 3255 observed reflections collected with a four-circle X-ray diffractometer), is a new mineral species from Mount Koashva, Khibina alkaline massif, Kola Peninsula, Russia. It is of pegmatitic origin. Associated minerals are K-feldspar, sodalite, cancrinite, natrolite, pectolite, aegirine, natrite, nacaphite, vitusite, fluorcaphite, belovite, umbite, lemmleinite-K, lomonosovite, lovozerite, phlogopite, sphalerite, and galena. The mineral was found in only one hand specimen of pegmatite rock as a corroded, irregularly shaped grain 2 3 mm across, intergrown with cancrinite, sodalite, and natrite. It is transparent, colorless with a white streak, a vitreous luster, and fluoresces pale whitish green under ultraviolet light. Megakalsilite has a Mohs hardness of 6, is brittle with a conchoidal fracture, and has no cleavage. Dmeas is 2.58(2) g/cm3, Dcalc is 2.62 g/cm3. Megakalsilite is uniaxial negative, non-pleochroic, 1.538(1), 1.531(1). The strongest five reflections in the X-ray powder-diffraction pattern [d in Å(I)(hkl)] are: 3.091(100)(222), 2.612(70)(060), 1.240(60)(4.10.1,066,583), 3.18(50)(141), and 1.674(50)(173). An electron-microprobe analysis gives: K2O 29.73, Na2O 0.02, FeO 0.04, Al2O3 32.38, SiO2 37.96, TiO2 0.01, sum 100.14 wt.%. The corresponding empirical formula is K0.997Na0.001Fe0.001Al1.003Si0.998O4 (based on O = 4), ideally KAlSiO4. The name megakalsilite is derived from the Greek (great) and kalsilite, in allusion to the fact that megakalsilite shares the same chemical formula with kalsilite, but its unit cell is 12 times larger than that of kalsilite. The crystal structure of megakalsilite, KAlSiO4, has been solved by direct methods and refined to an R1 index of 3.82% based on 3255 observed [Fo > 4 sigma(Fo)] unique reflections measured with MoK radiation on a conventional four-circle diffractometer. There are four Si sites, four Al sites, and six K sites in the ... Article in Journal/Newspaper kola peninsula ARPI - Archivio della Ricerca dell'Università di Pisa Kola Peninsula Koashva ENVELOPE(34.082,34.082,67.656,67.656) |
institution |
Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
topic |
megakalsilite new mineral specie polymorph crystal structure Khibina Kola Peninsula |
spellingShingle |
megakalsilite new mineral specie polymorph crystal structure Khibina Kola Peninsula KHOMYAKOV AP NECHELYUSTOV GN SOKOLOVA E BONACCORSI, ELENA MERLINO, STEFANO PASERO, MARCO Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
topic_facet |
megakalsilite new mineral specie polymorph crystal structure Khibina Kola Peninsula |
description |
Megakalsilite, KAlSiO4, hexagonal, a 18.1111(8), c 8.4619(4) Å, V 2403.7(2) Å3, c:a = 0.4672, space group P63, Z = 24, R = 0.039 (for 3255 observed reflections collected with a four-circle X-ray diffractometer), is a new mineral species from Mount Koashva, Khibina alkaline massif, Kola Peninsula, Russia. It is of pegmatitic origin. Associated minerals are K-feldspar, sodalite, cancrinite, natrolite, pectolite, aegirine, natrite, nacaphite, vitusite, fluorcaphite, belovite, umbite, lemmleinite-K, lomonosovite, lovozerite, phlogopite, sphalerite, and galena. The mineral was found in only one hand specimen of pegmatite rock as a corroded, irregularly shaped grain 2 3 mm across, intergrown with cancrinite, sodalite, and natrite. It is transparent, colorless with a white streak, a vitreous luster, and fluoresces pale whitish green under ultraviolet light. Megakalsilite has a Mohs hardness of 6, is brittle with a conchoidal fracture, and has no cleavage. Dmeas is 2.58(2) g/cm3, Dcalc is 2.62 g/cm3. Megakalsilite is uniaxial negative, non-pleochroic, 1.538(1), 1.531(1). The strongest five reflections in the X-ray powder-diffraction pattern [d in Å(I)(hkl)] are: 3.091(100)(222), 2.612(70)(060), 1.240(60)(4.10.1,066,583), 3.18(50)(141), and 1.674(50)(173). An electron-microprobe analysis gives: K2O 29.73, Na2O 0.02, FeO 0.04, Al2O3 32.38, SiO2 37.96, TiO2 0.01, sum 100.14 wt.%. The corresponding empirical formula is K0.997Na0.001Fe0.001Al1.003Si0.998O4 (based on O = 4), ideally KAlSiO4. The name megakalsilite is derived from the Greek (great) and kalsilite, in allusion to the fact that megakalsilite shares the same chemical formula with kalsilite, but its unit cell is 12 times larger than that of kalsilite. The crystal structure of megakalsilite, KAlSiO4, has been solved by direct methods and refined to an R1 index of 3.82% based on 3255 observed [Fo > 4 sigma(Fo)] unique reflections measured with MoK radiation on a conventional four-circle diffractometer. There are four Si sites, four Al sites, and six K sites in the ... |
author2 |
Khomyakov, Ap Nechelyustov, Gn Sokolova, E Bonaccorsi, Elena Merlino, Stefano Pasero, Marco |
format |
Article in Journal/Newspaper |
author |
KHOMYAKOV AP NECHELYUSTOV GN SOKOLOVA E BONACCORSI, ELENA MERLINO, STEFANO PASERO, MARCO |
author_facet |
KHOMYAKOV AP NECHELYUSTOV GN SOKOLOVA E BONACCORSI, ELENA MERLINO, STEFANO PASERO, MARCO |
author_sort |
KHOMYAKOV AP |
title |
Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
title_short |
Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
title_full |
Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
title_fullStr |
Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
title_full_unstemmed |
Megakalsilite, a new polymorph of KAlSiO4, from the Khibina alkaline massif, Kola Peninsula, Russia: mineral description and crystal structure |
title_sort |
megakalsilite, a new polymorph of kalsio4, from the khibina alkaline massif, kola peninsula, russia: mineral description and crystal structure |
publishDate |
2002 |
url |
http://hdl.handle.net/11568/205759 |
long_lat |
ENVELOPE(34.082,34.082,67.656,67.656) |
geographic |
Kola Peninsula Koashva |
geographic_facet |
Kola Peninsula Koashva |
genre |
kola peninsula |
genre_facet |
kola peninsula |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/000177081400016 volume:40 firstpage:961 lastpage:970 numberofpages:10 journal:CANADIAN MINERALOGIST http://hdl.handle.net/11568/205759 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036614004 |
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1792050312297578496 |