Whiteite-(MnMnMn), a new jahnsite-group mineral species from the Foote mine, North Carolina, USA, and chemical pressure effects in jahnsite-group minerals

2021 ◽  
pp. 1-17
Author(s):  
Ian E. Grey ◽  
Jason B. Smith ◽  
Anthony R. Kampf ◽  
W. Gus Mumme ◽  
Colin M. Macrae ◽  
...  
Keyword(s):  
North Carolina ◽  
Pressure Effects ◽  
Mineral Species ◽  
Chemical Pressure ◽  
Group Mineral

Investigations of chemical pressure effects on the valence behaviour of praseodymium intermetallics I: The Pr1−xYxSn3 family

1989 ◽  
Vol 154 (1) ◽  
pp. 115-120 ◽  
Author(s):  
F. Canepa ◽  
E.A. Franceschi ◽  
G.L. Olcese ◽  
R. Eggenhoffner
Keyword(s):  
Pressure Effects ◽  
Chemical Pressure

Vittinkiite, MnMn4[Si5O15], a member of the rhodonite group with a long history: definition as a mineral species

2020 ◽  
pp. 1-12
Author(s):  
Nadezhda V. Shchipalkina ◽  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Natalia V. Zubkova ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mineral Species ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
Triclinic Space Group ◽  
Group Mineral ◽  
Coordination Numbers ◽  
The Relationship ◽  
Mn Oxides

Abstract The rhodonite-group mineral with the idealised, end-member formula MnMn4[Si5O15] and the crystal chemical formula VIIM(5)MnVIM(1–3)Mn3VIIM(4)Mn[Si5O15] (Roman numerals indicate coordination numbers) is defined as a valid mineral species named vittinkiite after the type locality Vittinki (Vittinge) mines, Isokyrö, Western and Inner Finland Region, Finland. Vittinkiite is an isostructural analogue of rhodonite, ideally CaMn4[Si5O15], with Mn2+ > Ca at the M(5) site. Besides Vittinki, vitiinkiite was found in more than a dozen rhodonite deposits worldwide, however, it is significantly less common in comparison with rhodonite. The mineral typically forms pink to light pink massive, granular aggregates and is associated with quartz, rhodonite, tephroite, pyroxmangite and Mn oxides. Vittinkiite is optically biaxial (+), with α = 1.725(4), β = 1.733(4), γ = 1.745(5) and 2Vmeas = 75(10)° (589 nm). The chemical composition of the holotype (wt.%, electron microprobe) is: MgO 0.52, CaO, 0.93, MnO 51.82, FeO 1.26, ZnO 0.11, SiO2 46.48, total 101.12. The empirical formula calculated based on 15 O apfu is Mn4.71Ca0.11Fe0.11Mg0.08Zn0.01Si4.99O15. Vittinkiite is triclinic, space group P $\bar{1}$ , with a = 6.6980(3), b = 7.6203(3), c = 11.8473(5) Å, α = 105.663(3), β = 92.400(3), γ = 94.309(3)°, V = 579.38(7) Å3 and Z = 2. The crystal structure is solved on a single crystal to R1 = 3.85%. Polymorphism of MnSiO3 (rhodonite-, pyroxmangite-, garnet- and clinopyroxene-type manganese metasilicates) is discussed, as well as the relationship between vittinkiite and pyroxmangite, ideally Mn7[Si7O21], and the application of infrared spectroscopy for the identification of manganese pyroxenoids.

Chemical pressure effects on magnetic properties of A2FeMoO6 (A=Ca, Sr, and Ba)

2010 ◽  
Vol 173 (1-3) ◽  
pp. 44-46 ◽  
Author(s):  
Akira Isayama ◽  
Shogo Kadota ◽  
Hideomi Yui ◽  
Takao Sasagawa
Keyword(s):  
Magnetic Properties ◽  
Pressure Effects ◽  
Chemical Pressure

scholarly journals Chemical Pressure Effects on Pyrochlore Spin Ice

2012 ◽  
Vol 108 (20) ◽  
Author(s):  
H. D. Zhou ◽  
J. G. Cheng ◽  
A. M. Hallas ◽  
C. R. Wiebe ◽  
G. Li ◽  
...  
Keyword(s):  
Pressure Effects ◽  
Spin Ice ◽  
Chemical Pressure

scholarly journals Pressure effects in PrT2B2C (T = Co, Ni, Pt): Applied and chemical pressure

2011 ◽  
Vol 208 (9) ◽  
pp. 2159-2165 ◽  
Author(s):  
R. Falconi ◽  
A. Durán ◽  
M. Núñez-Regueiro ◽  
R. Escudero
Keyword(s):  
Pressure Effects ◽  
Chemical Pressure

Chemical pressure effects and valence fluctuations in Yb0.6Ca0.4Al2 and YbAl2 alloys: A photoemission investigation

1988 ◽  
Vol 65 (7) ◽  
pp. 743-747 ◽  
Author(s):  
I. Abbati ◽  
B. DeMichelis ◽  
A. Fasana ◽  
M. Sancrotti ◽  
A. Iandelli ◽  
...  
Keyword(s):  
Pressure Effects ◽  
Chemical Pressure ◽  
Valence Fluctuations

CARLGIESECKEITE-(Nd), NaNdCa3(PO4)3F, A NEW BELOVITE-GROUP MINERAL SPECIES FROM THE ILIMAUSSAQ ALKALINE COMPLEX, SOUTH GREENLAND

2012 ◽  
Vol 50 (2) ◽  
pp. 571-580 ◽  
Author(s):  
I. V. Pekov ◽  
N. V. Zubkova ◽  
T. A. Husdal ◽  
N. N. Kononkova ◽  
A. A. Agakhanov ◽  
...  
Keyword(s):  
Mineral Species ◽  
Alkaline Complex ◽  
Group Mineral
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