Carbocernaite from Bear Lodge, Wyoming: Crystal chemistry, paragenesis, and rare-earth fractionation on a microscale

Chakhmouradian, Anton R.; Cooper, M.; Reguir, Ekaterina P.; Moore, Meghan

doi:10.2138/am-2017-6046

Cited by 20 publications

(25 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The crystal structure of carbocernaite was originally solved by Voronkov and Pyatenko [36] in the space group Pb2 1 m, which was confirmed in [37]. However, the recent study of carbocernaite from Wyoming [38] revealed the presence of reflections that violated the above-mentioned space group, very similar to our observations concerning paratooite-(La) (see above). Therefore, the alternative space group was chosen as P11m (Table 6).…”

Section: Discussionsupporting

confidence: 88%

“…Carbocernaite, ideally CaSr(CO 3 ) 2 , was discovered by Bulakh et al [34] at the Vuoriyarvi complex, Northern Karelia, Russia. Recently, Chakhmouradian et al [38] investigated carbocernaite from Bear Lodge, Wyoming, USA, and demonstrated that the mineral can be described as a solid solution between CaSr(CO 3 ) 2 and NaREE(CO 3 ) 2 . The crystal structure of carbocernaite was originally solved by Voronkov and Pyatenko [36] in the space group Pb2 1 m, which was confirmed in [37].…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, it is of interest to reproduce the mineral under laboratory conditions, which would allow to investigate its structure and properties in more details. [38] * Crystallographic axes interchanged for the ease of comparison.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, the whole cation array in paratooite-(La) may be considered as a strongly distorted cation-ordered body-centered lattice. Figure 3 compares the crystal structure of paratooite-(La) (Figure 3a) with that of carbocernaite, ideally CaSr(CO 3 ) 2 [34][35][36][37][38]. It is obvious that the two crystal structures are very similar, with that of paratooite being the superstructure of carbocernaite.…”

Section: Structure Descriptionmentioning

confidence: 99%

See 3 more Smart Citations

Jahn-Teller Distortion and Cation Ordering: The Crystal Structure of Paratooite-(La), a Superstructure of Carbocernaite

et al. 2019

View full text Add to dashboard Cite

The crystal structure of paratooite-(La) has been solved using crystals from the type locality, Paratoo copper mine, near Yunta, Olary Province, South Australia, Australia. The mineral is orthorhombic, Pbam, a = 7.2250(3) Å, b = 12.7626(5) Å, c = 10.0559(4) Å, V = 927.25(6) Å 3 , and R 1 = 0.063 for 1299 unique observed reflections. The crystal structure contains eight symmetrically independent cation sites. The La site, which accommodates rare earth elements (REEs), but also contains Sr and Ca, has a tenfold coordination by seven carbonate groups. The Ca, Na1, and Na2 sites are coordinated by eight, eight, and six O atoms, respectively, forming distorted CaO 8 and Na1O 8 cubes, and Na 2 O 6 octahedra. The Cu site is occupied solely by copper and possess a distorted octahedral coordination with four short (1.941 Å) and two longer (2.676 Å) apical Cu-O bonds. There are three symmetrically independent carbonate groups (CO 3 ) 2− with the average bond lengths equal to 1.279, 1.280, and 1.279 Å for the C1, C2, and C3 sites, respectively. The crystal structure of paratooite-(La) can be described as a strongly distorted body-centered lattice formed by metal cations with (CO 3 ) 2− groups filling its interstices. According to the chemical and crystal-structure data, the crystal-chemical formula of paratooite-(La) can be described as (La 0.74 Ca 0.11 Sr 0.07 ) 4 CuCa(Na 0.75 Ca 0.15 )(Na 0.63 )(CO 3 ) 8 or REE 2.96 Ca 1.59 Na 1.38 CuSr 0.28 (CO 3 ) 8 . The idealized formula can be written as (La,Sr,Ca) 4 CuCa(Na,Ca) 2 (CO 3 ) 8 . The structure of paratooite is a 1 × 2 × 2 superstructure of carbocernaite, CaSr(CO 3 ) 2 . The superstructure arises due to the ordering of the chemically different Cu 2+ cations, on one hand, and Na + and Ca 2+ cations, on the other hand. The formation of a superstructure due to the cation ordering in paratooite-(La) compared to carbocernaite results in the multiple increase of structural complexity per unit cell. Therefore, paratooite-(La) versus carbocernaite represents a good example of structural complexity increasing due to the increasing chemical complexity controlled by different electronic properties of mineral-forming chemical elements (transitional versus alkali and alkaline earth metals).

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Structure Descriptionmentioning

confidence: 99%

See 2 more Smart Citations

Jahn-Teller Distortion and Cation Ordering: The Crystal Structure of Paratooite-(La), a Superstructure of Carbocernaite

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The transition from sulfide mineralization to sulfate mineralization presumably was caused by a change in oxidizing conditions in the fluid during the waning stages of metasomatism. As shown for the carbonatites from the Bear Lodge, the reason for this phenomenon could be an influx of external (meteoric) fluid [70,72].…”

mentioning

confidence: 94%

The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

et al. 2020

View full text Add to dashboard Cite

The Vuoriyarvi Devonian carbonatite–ijolite–pyroxenite–olivinite complex comprises several carbonatite fields: Neske Vara, Tukhta-Vara, and Petyayan-Vara. The most common carbonatites in the Tukhta-Vara and Neske-Vara fields are calciocarbonatites, which host several P, Fe, Nb, and Ta deposits. This paper focuses on the Petyayan-Vara field, in which the primary magmatic carbonatites are magnesian. The least altered magnesiocarbonatites are composed of dolomite with burbankite and are rich in REE (up to 2.0 wt. %), Sr (up to 1.2 wt. %), and Ba (up to 0.8 wt. %). These carbonatites underwent several stages of metasomatism. Each metasomatic event produced a new rock type with specific mineralization. The introduction of K, Si, Al, Fe, Ti, and Nb by a F-rich fluid (or fluid-saturated melt) resulted in the formation of high-Ti magnesiocarbonatites and silicocarbonatites, composed of dolomite, microcline, Ti-rich phlogopite, and Fe–Ti oxides. Alteration by a phosphate–fluoride fluid caused the crystallization of apatite in the carbonatites. A sulfate-rich Ba–Sr–rare-earth elements (REE) fluid (probably brine-melt) promoted the massive precipitation of ancylite and baryte and, to a lesser extent, strontianite, bastnäsite, and synchysite. Varieties of carbonatite that contain the highest concentrations of REE are ancylite-dominant. The influence of sulfate-rich Ba-Sr-REE fluid on the apatite-bearing rocks resulted in the dissolution and reprecipitation of apatite in situ. The newly formed apatite generation is rich in HREE, Sr, and S. During late-stage transformations, breccias of magnesiocarbonatites with quartz-bastnäsite matrixes were formed. Simultaneously, strontianite, quartz, calcite, monazite, HREE-rich thorite, and Fe-hydroxides were deposited. Breccias with quartz-bastnäsite matrix are poorer in REE (up to 4.5 wt. % total REE) than the ancylite-dominant rocks (up to 11 wt. % total REE).

show abstract

Raman Spectra of Minerals

Чуканов

Вигасина

2019

Vibrational (Infrared and Raman) Spectra of Minerals and Related Compounds

View full text Add to dashboard Cite

Carbocernaite from Bear Lodge, Wyoming: Crystal chemistry, paragenesis, and rare-earth fractionation on a microscale

Cited by 20 publications

References 41 publications

Jahn-Teller Distortion and Cation Ordering: The Crystal Structure of Paratooite-(La), a Superstructure of Carbocernaite

Jahn-Teller Distortion and Cation Ordering: The Crystal Structure of Paratooite-(La), a Superstructure of Carbocernaite

The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

Raman Spectra of Minerals

Contact Info

Product

Resources

About