Chemical and paragenetic data on gadolinite-group minerals from Baveno and Cuasso al Monte, southern Alps, Italy

Pezzotta, Federico; Diella, Valeria; Guastoni, Alessandro

doi:10.2138/am-1999-5-612

Cited by 44 publications

(26 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hingganites have been found in various types of geological settings: Granitic pegmatites [7,13], granodiorites [14], syenite gneisses [15], skarns [16], different types of metasomatites [6,17,18], and REE-rich Alpine-type hydrothermal mineralization [19].…”

Section: Introductionmentioning

confidence: 99%

Low-Temperature Crystal Chemistry of Hingganite-(Y), from the Wanni Glacier, Switzerland

Gorelova

Vereshchagin

Cuchet³

et al. 2020

Minerals

View full text Add to dashboard Cite

Hingganite from the Wanni glacier (Switzerland) was studied by means of energy dispersive and wavelength-dispersive spectroscopy, Raman spectroscopy, and low-temperature single-crystal X-ray diffraction. According to its chemical composition, the investigated mineral should be considered as hingganite-(Y). It showed a relatively high content of Gd, Dy, and Er and had limited content of lighter rare-earth element (REE), which is typical for Alpine gadolinite group minerals. The most intense Raman bands were 116, 186, 268, 328, 423, 541, 584, 725, 923, 983, 3383, and 3541 cm−1. Based on data of low-temperature [(−173)–(+7) °C] in situ single-crystal X-ray diffraction, it was shown that the hingganite-(Y) crystal structure was stable in the studied temperature range and no phase transitions occurred. Hingganite-(Y) demonstrated low volumetric thermal expansion (αV = 9(2) × 10−6 °C−1) and had a high thermal expansion anisotropy up to compression along one of the directions in the layer plane. Such behavior is caused by the shear deformations of its monoclinic unit cell.

show abstract

Section: Introductionmentioning

confidence: 99%

Low-Temperature Crystal Chemistry of Hingganite-(Y), from the Wanni Glacier, Switzerland

Gorelova

Vereshchagin

Cuchet³

et al. 2020

Minerals

View full text Add to dashboard Cite

show abstract

“…No common view on the nature of the enrichment or depletion of fergusonite in particular elements of the HREE group exists (Pezzotta et al, 1999;Masau et al, 2000). It may be suggested that this phenomenon is related to some deviation of ytterbium properties from the standard properties of other REE.…”

Section: Discussion: Regular Variations In the Composition Of Major Tmentioning

confidence: 99%

Tantalum-niobium mineralization of the Taikeu ore cluster, the Polar Urals

et al. 2009

View full text Add to dashboard Cite

The Taikeu ore cluster comprises four tantalum-bearing ore deposits: Taikeu, Ust-Mramorny, Longotyugan, and Neudachny. Their ores are related to microcline-albite and less frequent quartz-albite-mica (phengite) metasomatic rocks replacing granites. The major ore minerals belong to the fergusonite and pyrochlore groups (mainly plumbopyrochlore). The compositional evolution of these minerals is considered in detail. High-Yb fergusonite containing up to 22-27 wt % Yb 2 O 3 was established in the ore cluster for the first time. Its formula is ({Yb 0.30 Er 0.15 Dy 0.05 Lu 0.04 Tm 0.04 …} 0.61 Y 0.39 )[Nb 0.99 Ta 0.01 ]O 3.96 . The density of this mineral determined by microvolumetric method is 6.47 ± 0.06 g/cm 3 . Fergusonite evolves from high-Yb to low-Yb varieties, with relatively small variations in Er and Dy. It is suggested that this fractionation trend is caused by high solubility of Yb 2+ complexes (primarily, fluoride complexes) in aqueous fluid during albitization. The chemical composition of the pyrochlore-group minerals evolves as follows: Na+Ca U+Th Pb. Plumbopyrochlore was formed at the late metasomatic stage of tantalum-niobium mineralization. The characteristic features of this stage are a high oxidation potential, on the one hand, and a low activity of sulfide sulfur, on the other hand.

show abstract

“…commun., 2013) with single crystals of more than 10 kg (Müller et al, 2010a). Gadolinite is a rare REE mineral which typically occurs in chemically evolved NYF-type pegmatites (e.g., Pezzotta et al, 1999). Quartz of the amazonite-cleavelandite pegmatites is not only enriched in Ge (mean 5.6 ± 2.8 µgg -1 ; n = 26) but also in Li (mean 9.1 ± 6.1 µgg -1 ; n = 26), however Ti (mean 7.5 ± 7.2 µgg -1 ; n = 26) is depleted compared to pegmatites elsewhere in the field.…”

Section: Quartz Compositional Variations Within Pegmatite Fieldsmentioning

confidence: 99%

The Chemistry of Quartz in Granitic Pegmatites of Southern Norway: Petrogenetic and Economic Implications

et al. 2015

View full text Add to dashboard Cite

Trace element concentrations in quartz from 188 granitic pegmatites in the Froland and Evje-Iveland pegmatite fields, southern Norway, have been determined to establish exploration targets for high-purity quartz and to gain a better understanding of the genesis of pegmatites hosting these deposits. Both pegmatite fields were formed during the Sveconorwegian (Grenvillian) orogeny (1145-900 Ma) at the western margin of the Fennoscandian Shield.In situ raster analyses within single quartz crystals were undertaken by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS); spot size 75 µm) to assess levels of lattice-bound impurities, rather than mineral and fluid inclusions that are relatively easily removed during high-purity quartz processing. Quartz in the Froland pegmatites has relatively pure and homogeneous compositions containing 46 ± 24 µgg -1 Al, 8 ± 3 µgg -1 Ti, 1.4 ± 0.8 µgg -1 Ge, and 11 ± 7 µgg -1 Li. The Ti-in-quartz geothermobarometer gives an average pegmatite crystallization temperature of 537° ± 39°C. Temperature estimates are highest along the northwestern margin of the pegmatite field (>550°C), whereas the most differentiated pegmatites occur toward the northeast. The area of greatest economic potential for high-purity quartz lies just north of the central part of the field where individual pegmatites contain >1 million metric tons (Mt) quartz with low average trace element contents of 67 ± 11 µgg -1 . From mineral-chemical criteria, and a range of other geologic factors, we propose that pegmatite melts in the Froland field were generated by fluid-present crustal melting at about 1060 Ma, in zones of localized high-strain deformation during progressive thrusting along the Porsgrunn-Kristiansand fault zone.Quartz in the Evje-Iveland pegmatites has more variable compositions with 69 ± 57 µgg -1 Al, 19 ± 11 µgg -1 Ti, 2.3 ± 1.8 µgg -1 Ge, and 7 ± 5 µgg -1 Li. From its Ti content, it crystallized at temperatures of 613° ± 70°C. The regional spatial distribution of Ti-in-quartz temperatures appears irregular mainly due to the scattered distributions of chemical evolved pegmatites with "amazonite"-"cleavelandite" replacement zones, which show crystallization temperatures down to 442°C. Quartz from the Evje-Iveland pegmatites is unlikely to be of current economic interest due to its moderate to high trace element contents, heterogeneous chemistry, and low volume. The Evje-Iveland pegmatites show no apparent genetic link to a granite intrusion; instead they probably formed as a result of partial melting at the depth of their amphibolite country rocks at around 910 Ma. This is related to a regional low-pressure/high-temperature metamorphic event at about 930 to 920 Ma.

show abstract

Chemical and paragenetic data on gadolinite-group minerals from Baveno and Cuasso al Monte, southern Alps, Italy

Cited by 44 publications

References 3 publications

Low-Temperature Crystal Chemistry of Hingganite-(Y), from the Wanni Glacier, Switzerland

Low-Temperature Crystal Chemistry of Hingganite-(Y), from the Wanni Glacier, Switzerland

Tantalum-niobium mineralization of the Taikeu ore cluster, the Polar Urals

The Chemistry of Quartz in Granitic Pegmatites of Southern Norway: Petrogenetic and Economic Implications

Contact Info

Product

Resources

About