scholarly journals Princivalleite, Na(Mn2Al)Al6(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup from Veddasca Valley (Varese, Italy)

2022 ◽  
pp. 1-30
Author(s):  
Ferdinando Bosi ◽  
Federico Pezzotta ◽  
Henrik Skogby ◽  
Alessandra Altieri ◽  
Ulf Hålenius ◽  
...  
1993 ◽  
Vol 31 (2) ◽  
pp. 331-336 ◽  
Author(s):  
R. Brasso ◽  
G. Lucchetti ◽  
L. Zefiro ◽  
A. Palenzona

2008 ◽  
Vol 72 (5) ◽  
pp. 1083-1101 ◽  
Author(s):  
W. H. Paar ◽  
Y. Moëlo ◽  
N. N. Mozgova ◽  
N. I. Organova ◽  
C. J. Stanley ◽  
...  

AbstractCoiraite, ideally (Pb,Sn2+)12.5As3Fe2+Sn4+S28, occurs as an economically important tin ore in the large Ag-Sn-Zn polymetallic Pirquitas deposit, Jujuy Province, NW-Argentina. The new mineral species is the As derivative of franckeite and belongs to the cylindrite group of complex Pb sulphosalts with incommensurate composite-layered structures. It is a primary mineral, frequently found in colloform textures, and formed from hydrothermal solutions at low temperature. Associated minerals are franckeite, cylindrite, pyrite-marcasite, as well as minor amounts of hocartite, Ag-rich rhodostannite. arsenopyrite and galena. Laminae of coiraite consist of extremely thin bent platy crystals up to 50 urn long. Electron microprobe analysis (n = 31) gave an empirical formula Pb11.21As2.99Ag0.13Fe1.10Sn6.13S28.0 close to the ideal formula (Pb11.3Sn2+1.2)Σ=12.5As3Fe2+Sn4+S28. Coiraite has two monoclinic sub-cells, Q (pseudotetragonal) and H (pseudohexagonal). Q: a 5.84(1) Å, b 5.86(1) Å, c 17.32(1) Å, β 94.14(1)°, F 590.05(3) Å3, Z = 4, a:b:c = 0.997:1:2.955; H (orthogonal setting): a 6.28(1) Å, b 3.66(1) Å, c 17.33(1) Å, β 91.46(1)°, V398.01(6) Å3, Z = 2, a∶b∶c = 1.716∶1∶4.735. The strongest Debye-Scherrer camera X-ray powder-diffraction lines [d in Å, (I), (hkl)] are: 5.78, (20), (Q and H 003); 4.34, (40), (Q 004); 3.46, (30), (Q and H 005); 3.339, (20), (Q 104); 2.876, (100), (Q and H 006); 2.068, (60), (Q 220).


Author(s):  
B. W. Anderson ◽  
C. J. Payne ◽  
G. F. Claringbull

In October 1945 Count Taaffe, a brilliant if unorthodox Dublin gemmologist, in the course of examining a motley collection of gemstones, came across a small mauve stone which puzzled him greatly. The stone had the appearance, and most of thc characters, of spinel, but afforded clear evidence of double refraction. As recounted below, this stone was later found to belong to an entirely new mineral species-—the only case hitherto known where a mineral has been first encountered as a faceted gem.


2016 ◽  
Vol 101 (11) ◽  
pp. 2539-2543 ◽  
Author(s):  
Robert T. Downs ◽  
William W. Pinch ◽  
Richard M. Thompson ◽  
Stanley H. Evans ◽  
Lauren Megaw

2019 ◽  
Vol 64 (11) ◽  
pp. 1196-1205
Author(s):  
E. M. Spiridonov

In the plagioperidotite of the ultamafite-mafic Yoko-Dovyren intrusion captured by low-grad metamorphism (NGM) under conditions of the prenite-pumpelliite facies (PPF), mobilization of Ba, Cl and Sr is observed The content of barium in plagioperidotite ranges from 36 to 313 (an average of 130 g / t); strontium from 25 to 169 (an average of 86 g / t); Ba / Sr value varies from 0.5 to 4 (on average 1.5). Barium minerals phlogopite and plagioclase; chlorine chloroferrisadanagite from inclusions in alumochromite, late-magmatic phlogopite, potassium chlorate ferropargassite and chlorapatite in the margins of sulphide nests. During the NGM processes, these minerals were replaced by chlorites, tremolite, diopside, which included very little Ba and Cl. In the areas of barium minerals development, plagioperidotites contain 348518 g/t of barium and 46 g/t of strontium, which indicates the redistribution of Ba and the removal of Sr. Metamorphogenic barium minerals non-strontium barite and Ba-Fe-Cl mica chloro-dominant ferrokinochitalit. They coexist with the minerals of the rodingite association hydrogarnet, tremolite, diopside, chlorite, antigorite, magnetite, hydroxylapatite. Ferrokosnoshitalit replaces phlogopite, plagioclase, sulfides, contains up to 21 wt. % BaO, 31% FeO, 11% Cl and has a iron index of f = 75.890.5. The composition of the most chlorine-rich individual responds (Ba0.83K0.16)0.99(Fe2+2.63Mg0.28Fe3+0.04Al0.02Cr0.01Mn0.01)3[(Cl1.86OH0.12S0.02)2/Al1.86Si2.14O10]. Since Yoko-Dovyrenskiy ferrokynosalital is chlordominant, this is a new mineral species.


2007 ◽  
Vol 45 (6) ◽  
pp. 1511-1517 ◽  
Author(s):  
M. Ohnishi ◽  
I. Kusachi ◽  
S. Kobayashi

2004 ◽  
Vol 42 (1) ◽  
pp. 121-124 ◽  
Author(s):  
K. T. Tait ◽  
F. C. Hawthorne ◽  
J. D. Grice ◽  
J. L. Jambor ◽  
W. W. Pinch

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