scholarly journals The new mineral tomiolloite, Al12(Te4+O3)5[(SO3)0.5(SO4)0.5](OH)24: a unique microporous tellurite structure

2022 ◽  
Keyword(s):  
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.


1975 ◽  
Vol 14 (8) ◽  
pp. 368-375 ◽  
Author(s):  
E. A. Jobbins ◽  
Anne E. Tresham ◽  
B. R. Young
Keyword(s):  

1889 ◽  
Vol s3-37 (217) ◽  
pp. 67-70 ◽  
Author(s):  
H. L. Wells
Keyword(s):  

Priroda ◽  
2018 ◽  
pp. 12-20
Author(s):  
R. Rastsvetaeva ◽  
◽  
S. Aksenov ◽  
Keyword(s):  

Priroda ◽  
2018 ◽  
pp. 18-23
Author(s):  
S. Aksenov ◽  
◽  
R. Rastsvetaeva ◽  
Keyword(s):  

Author(s):  
S. Sukhanova ◽  
N. Pozdnyakova ◽  
F. Yaroslavtsev

The results of researches on the development of new mineral feed additives based on raw materials produced by Uralchem and the study of the eff ectiveness of their use in the rations of lactating cows have been presented in the article. The experiment has been carried out in the conditions of LLC “PF Barabinskoe” in the Dalmatovsky area in the Kurgan region where 3 groups of lactating cows of Black-and-White breed have been formed. Animals in the control group have been received the ration adopted in the farm, the 1st experimental group with the additive RusMA No. 1 at a dose of 150 g, the 2nd experimental group– with the additive RusMA No. 2 at the dose of 350 g. The use of experimental mineral additives in feeding lactating cows allowed us to increase their milk productivity and profi tability of production. At the same time, the best eff ectiveness was shown by the additive RusMA No. 2 at the dose of 350 g/head/day. The use of RusMA additives during the experiment period (105 days) allowed to increase the milk productivity of cows in the 1st experimental group by 6,03 % and in the 2nd experimental group by 8,24 %. Taking into account the fat content in milk, this diff erence was 6,31 and 8,53 %, respectively. The energy value of milk from cows of the experimental groups was higher compared to the control group by 2,45 and 1,76 %, respectively. According to the content of dry matter in milk, cows of the 2nd experimental group exceeded the control and 1st experimental group by 0,39 and 0,12 abs.%, respectively. The maximum milk fat content has been observed in the milk of cows of the 1st experimental group by 0,03 and 0,01 abs.% more than in the control and 2nd experimental groups, respectively. In terms of protein content, the cows of the 2nd experimental group signifi cantly exceeded the control group by 0,10 abs.% and the 1st experimental by 0,04 abs.%. The content of milk sugar in the 2nd experimental group was higher than in the control by 0,30 abs.% and compared to the 1st experimental by 0,11 %. Signifi cantly more calcium and phosphorus were contained in the milk of cows of the 2nd experimental group by 4,58 % (Р ≤ 0,001) and 2,86 % (Р ≤ 0,05), compared with the control group. The expenditures of feed in the EFU for the production of 1 kg of milk in animals of the 2nd experimental group was less by 5,13 % than in control cows and by 2,63 % compared to the 1st experimental group. The prime cost of 1 centner of milk was lower in the 2nd experimental group by 3,94 %, in the 1st experimental group by 2,65 % compared to the control group. The level of profi tability of milk production in the 2nd experimental group was higher by 9,0 and 1,0 abs.% in comparison with the control and 1st experimental groups, respectively.


1993 ◽  
Vol 31 (2) ◽  
pp. 331-336 ◽  
Author(s):  
R. Brasso ◽  
G. Lucchetti ◽  
L. Zefiro ◽  
A. Palenzona

2020 ◽  
Vol 58 (5) ◽  
pp. 549-562
Author(s):  
Anatoly V. Kasatkin ◽  
Fabrizio Nestola ◽  
Radek Škoda ◽  
Nikita V. Chukanov ◽  
Atali A. Agakhanov ◽  
...  

ABSTRACT Hingganite-(Nd), ideally Nd2□Be2Si2O8(OH)2, is a new gadolinite group, gadolinite supergroup mineral discovered at Zagi Mountain, near Kafoor Dheri, about 4 km S of Warsak and 30 km NW of Peshawar, Khyber Pakhtunkhwa Province, Pakistan. The new mineral forms zones measuring up to 1 × 1 mm2 in loose prismatic crystals up to 0.7 cm long, where it is intergrown with hingganite-(Y). Other associated minerals include aegirine, microcline, fergusonite-(Y), and zircon. Hingganite-(Nd) is dark greenish-brown, transparent, has vitreous luster and a white streak. It is brittle and has a conchoidal fracture. No cleavage or parting are observed. Mohs hardness is 5½–6. Dcalc. = 4.690 g/cm3. Hingganite-(Nd) is non-pleochroic, optically biaxial (+), α = 1.746(5), β = 1.766(5), γ = 1.792(6) (589 nm). 2Vmeas. = 80(7)°; 2Vcalc. = 84°. Dispersion of optical axes was not observed. The average chemical composition of hingganite-(Nd) is as follows (wt.%; electron microprobe, BeO, B2O3, and Lu2O3 content measured by LA-ICP-MS; H2O calculated by stoichiometry): BeO 9.64, CaO 0.45, MnO 0.10, FeO 3.03, B2O3 0.42, Y2O3 8.75, La2O3 1.63, Ce2O3 12.89, Pr2O3 3.09, Nd2O3 16.90, Sm2O3 5.97, Eu2O3 1.08, Gd2O3 5.15, Tb2O3 0.50, Dy2O3 2.50, Ho2O3 0.33, Er2O3 0.84, Tm2O3 0.10, Yb2O3 0.44, Lu2O3 0.04, ThO2 0.13, SiO2 23.55, H2O 2.72, total 100.25. The empirical formula calculated on the basis of 2 Si apfu is (Nd0.513Ce0.401Y0.395Sm0.175Gd0.145Pr0.096Dy0.068La0.051Ca0.041Eu0.031Er0.022Tb0.014Yb0.011Ho0.009Tm0.003Th0.003Lu0.001)Σ1.979(□0.778Fe2+0.215Mn0.007)Σ1.000(Be1.967B0.062)Σ2.029Si2O8.46(OH)1.54. Hingganite-(Nd) is monoclinic, space group P21/c with a = 4.77193(15), b = 7.6422(2), c = 9.9299(2) Å, β = 89.851(2)°, V = 362.123(14) Å3, and Z = 2. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 6.105 (95) (011), 4.959 (56) (002), 4.773 (100) (100), 3.462 (58) (102), 3.122 , 3.028 (61) (013), 2.864 (87) (121), 2.573 (89) (113). The crystal structure of hingganite-(Nd) was refined from single-crystal X-ray diffraction data to R = 0.034 for 2007 unique reflections with I > 2σ(I). The new mineral is named as an analogue of hingganite-(Y), hingganite-(Yb), and hingganite-(Ce), but with Nd dominant among the rare earth elements.


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