Diskussion:Krotit

message: im folgenden die wichtigsten eckdaten aus dem abstract der publikation im
===American Mineralogist, Volume 96, pages 709–715, 2011===
Krotite, CaAl2O4, a new refractory mineral from the NWA 1934 meteorite
Chi Ma,1,* anthony R. KaMpf,2 haRold C. Connolly JR.,3,4,5 John R. BeCKett,1 GeoRGe R. RossMan,1 stuaRt a. sweeney sMith,4,6 and devin l. sChRadeR5
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, U.S.A. 2Mineral Sciences Department, Natural History Museum of Los Angeles County, Los Angeles, California 90007, U.S.A. 3Department of Physical Sciences, Kingsborough Community College of CUNY, Brooklyn, New York 11235 and Earth and Environmental Sciences, The Graduate Center of CUNY, New York, New York 10024, U.S.A. 4Department of Earth and Planetary Sciences, American Museum of Natural History, New York, New York 10024, U.S.A. 5Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, U.S.A. 6Department of Geology, Carleton College, Northfield, Minnesota 55057, U.S.A.
====Zitate aus dem Abstract:====
* chemical composition is (wt%) Al2O3 63.50, CaO 35.73, sum 99.23, (electron microprobe analysis) with an empirical formula calculated on the basis of 4 O atoms of Ca1.02Al1.99O4. 
* monoclinic, P21/n; a = 8.6996(3), b = 8.0994(3), c = 15.217(1) Å, β = 90.188(6), and Z = 12 (Single-crystal XRD)
* It has a stuffed tridymite structure, which was refined from single-crystal data to R1 = 0.0161 for 1014 Fo > 4σF reflections. 
* colorless and transparent with a vitreous luster and white streak. 
* Mohs hardness is ~61⁄2. 
* brittle, with a conchoidal fracture. 
* calculated density is 2.94 g/cm3.
* biaxial (–), α = 1.608(2), β = 1.629(2), γ = 1.635(2) (white light), 2Vmeas = 54.4(5)°, and 2Vcalc = 55.6°. 
* No dispersion was observed.
* The optical orientation is X = b; Y ≈ a; Z ≈ c. 
* Pleochroism is colorless to very pale gray, X > Y = Z. 
* Krotite is a low-pressure CaAl2O4 mineral, 
* likely formed by condensation or crystallization from a melt in the solar nebula. This is the first reported occurrence of krotite in nature and it is one of the earliest minerals formed in the solar system. (nicht signierter Beitrag von 46.124.91.80 (Diskussion) 16:32, 10. Mai 2011 (CEST)
thread_title:  Materialien zur ergänzung des Artikels 

message: Krotite, CaAl2O4, a new refractory mineral from the NWA 1934 meteorite
Chi Ma,1,* anthony R. KaMpf,2 haRold C. Connolly JR.,3,4,5 John R. BeCKett,1 GeoRGe R. RossMan,1 stuaRt a. sweeney sMith,4,6 and devin l. sChRadeR5
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, U.S.A. 2Mineral Sciences Department, Natural History Museum of Los Angeles County, Los Angeles, California 90007, U.S.A. 3Department of Physical Sciences, Kingsborough Community College of CUNY, Brooklyn, New York 11235 and Earth and Environmental Sciences, The Graduate Center of CUNY, New York, New York 10024, U.S.A. 4Department of Earth and Planetary Sciences, American Museum of Natural History, New York, New York 10024, U.S.A. 5Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, U.S.A. 6Department of Geology, Carleton College, Northfield, Minnesota 55057, U.S.A.
====Zitate aus dem Abstract:====
* chemical composition is (wt%) Al2O3 63.50, CaO 35.73, sum 99.23, (electron microprobe analysis) with an empirical formula calculated on the basis of 4 O atoms of Ca1.02Al1.99O4. 
* monoclinic, P21/n; a = 8.6996(3), b = 8.0994(3), c = 15.217(1) Å, β = 90.188(6), and Z = 12 (Single-crystal XRD)
* It has a stuffed tridymite structure, which was refined from single-crystal data to R1 = 0.0161 for 1014 Fo > 4σF reflections. 
* colorless and transparent with a vitreous luster and white streak. 
* Mohs hardness is ~61⁄2. 
* brittle, with a conchoidal fracture. 
* calculated density is 2.94 g/cm3.
* biaxial (–), α = 1.608(2), β = 1.629(2), γ = 1.635(2) (white light), 2Vmeas = 54.4(5)°, and 2Vcalc = 55.6°. 
* No dispersion was observed.
* The optical orientation is X = b; Y ≈ a; Z ≈ c. 
* Pleochroism is colorless to very pale gray, X > Y = Z. 
* Krotite is a low-pressure CaAl2O4 mineral, 
* likely formed by condensation or crystallization from a melt in the solar nebula. This is the first reported occurrence of krotite in nature and it is one of the earliest minerals formed in the solar system. (nicht signierter Beitrag von 46.124.91.80 (Diskussion) 16:32, 10. Mai 2011 (CEST)
thread_title: American Mineralogist, Volume 96, pages 709–715, 2011

message: * chemical composition is (wt%) Al2O3 63.50, CaO 35.73, sum 99.23, (electron microprobe analysis) with an empirical formula calculated on the basis of 4 O atoms of Ca1.02Al1.99O4. 
* monoclinic, P21/n; a = 8.6996(3), b = 8.0994(3), c = 15.217(1) Å, β = 90.188(6), and Z = 12 (Single-crystal XRD)
* It has a stuffed tridymite structure, which was refined from single-crystal data to R1 = 0.0161 for 1014 Fo > 4σF reflections. 
* colorless and transparent with a vitreous luster and white streak. 
* Mohs hardness is ~61⁄2. 
* brittle, with a conchoidal fracture. 
* calculated density is 2.94 g/cm3.
* biaxial (–), α = 1.608(2), β = 1.629(2), γ = 1.635(2) (white light), 2Vmeas = 54.4(5)°, and 2Vcalc = 55.6°. 
* No dispersion was observed.
* The optical orientation is X = b; Y ≈ a; Z ≈ c. 
* Pleochroism is colorless to very pale gray, X > Y = Z. 
* Krotite is a low-pressure CaAl2O4 mineral, 
* likely formed by condensation or crystallization from a melt in the solar nebula. This is the first reported occurrence of krotite in nature and it is one of the earliest minerals formed in the solar system. (nicht signierter Beitrag von 46.124.91.80 (Diskussion) 16:32, 10. Mai 2011 (CEST)
thread_title: Zitate aus dem Abstract:

message: http://ammin.geoscienceworld.org/content/94/5-6/746
Ist der Krotit die Normaldruckmodifikation von Dmitryivanovit?
Ist das Material vielleicht identisch mit dem synthetisch hergestellten CaAl2O4 als Lumineszenz-MAterial?
http://www.sciencedirect.com/science/article/pii/S0025540802010097 
Solubility of SrAl2O4 in CaAl2O4 - a high resolution powder diffraction study
By: Prodjosantoso, A. K.; Kennedy, B. J.
The solid soly. of the SrAl2O4-CaAl2O4 system has been investigated using high resoln. synchrotron powder diffraction methods.  Anal. of the patterns shows there is a limited compn. range at which single phase samples can be obtained,0.25 < x > 0.75 for the series Ca1-xSrxAl2O4.  At intermediate compns. up to three phases are obsd., two monoclinic and one hexagonal.  The temp. dependence of the structures is also described.
oder 
Structural analysis for novel materials exhibiting exotic properties. III. Correlation between structure and mechanoluminescence
By: Kubozono, Hiroto; Zheng, X. G.; Yamada, Hiroshi; Xu, C. N.
Rikogakubu Shuho (Saga Daigaku) (2006), 35, (1), 23-27. Publisher: (Saga Daigaku Rikogakubu, ) CODEN:RFSSDV ISSN:0385-6186
The correlation between the crystal structure and mechanoluminescence is explored.  Structural anal. was carried out on mechanoluminescent material SrAl2O4:Eu2+ and luminescent material CaAl2O4:Eu2+.  These 2 materials have similar crystal structures but show contrastingly different light-emission property.  Correlation between the lattice anisotropy and the mechanoluminescence is revealed.
MfG --Krizu (Diskussion) 12:10, 20. Nov. 2012 (CET)
thread_title:  Bezug zu anderen Stoffen - CAS 12042-68-1 

message: Ist die QS noch aktuell oder kann sie weg? Was wurde eigentlich kritisiert (ich sehe keine Liste, kann also nicht abhaken)? --GelberBaron (Diskussion) 13:28, 14. Feb. 2015 (CET)
replies: text: Ist nach Überarbeitung erledigt. Hab's rausgenommen. -- Ra'ike Disk. LKU WPMin 23:32, 14. Feb. 2015 (CET)
thread_title:  QS (erl.)