Oxybismutomicrolite

Oxybismutomicrolite
General and classification
other names	IMA 2019-047
chemical formula	(Bi 1.33 □ 0.67 ) Σ = 2 Ta 2 O 6 O [(Bi 3+ , #) 2 ] Σ4 + Ta 2 O 6 O with # = Na + , Ca 2+ and □ (Bi, Na, Ca) 2 (Ta, Ti, Nb, Sn) 2 O 6 (O, F)
Mineral class (and possibly department)	Oxides and hydroxides
System no. to Strunz and to Dana	4.DH.15 ( 8th edition : IV / C.18) 02/08/02. ##
Crystallographic Data
Crystal system	cubic
Crystal class ; symbol	cubic hexakisoctahedral; 4 / m  3  2 / m
Space group	Fd 3 m (No. 227)
Lattice parameters	a  = 10.4746  Å
Formula units	Z  = 8
Frequent crystal faces	{111}
Physical Properties
Mohs hardness	≈ 5; VHN 100 = 609 kg / mm²
Density (g / cm 3 )	6.98 (measured); 7,056 (calculated)
Cleavage	no
Break ; Tenacity	uneven; brittle
colour	black
Line color	gray-white
transparency	opaque, translucent in thin splinters
shine	Resin gloss
Crystal optics
Refractive index	n  = 2.184 (calculated)
Optical character	isotropic
Other properties
Chemical behavior	insoluble in cold HCl and HNO 3
Special features	no fluorescence in UV light

Oxybismutomicrolite is a very rare mineral from the mineral class of oxides and hydroxides . It crystallizes in the cubic crystal system with the composition [(Bi ³⁺ , #) ₂ ] ^{Σ4 +} Ta ₂ O ₆ O, is thus a bismuth - tantalate with additional oxygen ions . The symbol # stands for the possible incorporation of sodium as Na ⁺ and / or calcium as Ca ²⁺ in the crystal structure or for the occurrence of vacancies (defects) marked with the symbol □, as they occur with minerals that are deficient in cations.

Oxybismutomicrolite is found in the form of indistinct octahedral crystals up to 1 mm in size and granular aggregates up to 1 mm in diameter. Small crystals and aggregates are homogeneous, while larger crystals a clear zonation with zones of Bi -rich Fluornatromikrolith have the type locality of Oxybismutomikroliths is the gear shaped pegmatite "Solnechnaja" (the "sunny", Russian Солнечная ) ( coordinates of the pegmatite "Solnechnaja" ) in Pegmatite field "Malkhan" (also "Malchan" or "Malechansk") near Krasny Chikoi , approx. 320 km southwest of Chita and 200 km southeast of Ulan-Ude , Transbaikalia region ( Russian Забайкальский край ) in the Federal District of Siberia of the Russian Federation .

Etymology and history

The term bismuth microlite ( Russian Висмутомикролит ) was originally introduced by NE Zalashkova & MV Kukharchik for a new microlith variety from an unspecified vein-shaped pegmatite in the Russian Altai . However, this mineral contained too little Bi and later turned out to be fluorine atomic microlite. A few years later, Oleg von Knorring and Mary Mrose described a new bismuth mineral from "Wampewo Hill", Kingdom of Buganda , Uganda , with the formula (Bi, Ca) (Ta, Nb) ₂ O ₆ (OH) as "West Grenite". In 1977 Donald David Hogarth rejected the name “Westgrenite” in the first “Classification and nomenclature of the pyrochlore group” (1977) in favor of “bismuth microlite” in order to underline the fact that the mineral belongs to the microlite subgroup of the pyrochlore group. The choice was made on the basis of the chemical composition with bismuth and the crystal-chemical relationship with the representatives of the microlith group. Since the mineral is probably a mixture, it was discredited by Daniel Atencio and colleagues. Even in later years, bi-rich microliths were repeatedly described, often under the name bismuth microlite - but they represent all other representatives of the pyrochlore upper group (pyrochlore supergroup).

In September 1985, during work on the northwest side of the "Solnechnaja" pegmatite in the "Malkhan" pegmatite field, a 3 m × 2.5 m × 1.5 m large miarole was encountered, which in addition to up to 50 cm × 25 cm large smoky quartz crystals, watermelon tourmalines up to 18 cm × 15 cm in size and perfect cleavelandite and lepidolite crystals as well as many bismuth-containing phases contained a representative of the pyrochlore upper group with unusually high bismuth contents. This was characterized by the absence of any signs of metamictization , which was due to the almost complete absence of uranium and thorium . After determining the physical, chemical and X-ray diffractometric properties, it turned out to be a new representative of this group and was submitted to the International Mineralogical Association (IMA), which recognized it in 2019 under the provisional designation "IMA 2019-047". The first scientific description of this mineral took place in 2020 by an international research team with the Russian mineralogist Anatoly V. Kasatkin as well as Sergey N. Britvin, Igor S. Peretyazhko, Nikita V. Chukanov, Radek Škoda and Atali A. Agakhanov in the English science magazine “Mineralogical Magazin ". The authors named the new mineral in accordance with the nomenclature of the pyrochlore upper group due to its chemical composition with an A position dominated by bismuth , B position dominated by Ta, and Y position dominated by oxygen as oxybismuth microlite ( Russian Оксивисмутомикролит , English Oxybismutomicrol ) .

The type material for oxybismutomicrolite (holotype) is kept under catalog number 5409/1 in the systematic collection of the Mineralogical Museum " Alexander Evgenjewitsch Fersman " of the Russian Academy of Sciences in Moscow .

classification

The current classification of the International Mineralogical Association (IMA) counts the oxybismutomicrolite to the pyrochlore upper group with the general formula A _{2– m} B ₂ X _{6– w} Y _{1– n} , in which A , B , X and Y different positions in the structure the minerals of the pyrochlore upper group with A = Na, Ca, Sr, Pb ²⁺ , Sn ²⁺ , Sb ³⁺ , Y, U, □, or H ₂ O; B = Ta, Nb, Ti, Sb ⁵⁺ or W; X = O, OH or F and Y = OH ^- , F, O, □, H ₂ O or very large (>> 1.0 Å) monovalent cations such as K, Cs or Rb. To pyrochlore supergroup include not only Oxybismutomikrolith still Fluorcalciomikrolith , Fluornatromikrolith , Hydroxycalciomikrolith , Hydrokenomikrolith , Hydroxykenomikrolith , Kenoplumbomikrolith , Oxynatromikrolith , Oxystannomikrolith , Oxystibiomikrolith , Cesiokenopyrochlor , Fluorcalciopyrochlor , Fluornatropyrochlor , Hydrokenopyrochlor , Hydropyrochlor , Hydroxycalciopyrochlor , Hydroxykenopyrochlor , Hydroxymanganopyrochlor , Hydroxynatropyrochlor , Oxycalciopyrochlor , Fluorcalcioroméit , Hydroxycalcioroméit , Hydroxyferroroméit , Oxycalcioroméit , Oxyplumboroméite , Hydrokenoelsmoreit , Hydroxykenoelsmoreit , Fluornatrocoulsellit and Hydrokenoralstonit . Oxybismutomicrolite, together with fluorocalciomicrolite, fluoronatromicrolite, hydroxycalciomicrolite, hydrokenomicrolite, hydroxykenomicrolite, kenoplumbomicrolite, oxynatromicrolite, oxystibiomicrolite and oxystannomicrolite, form the microlith group within the pyrochlore upper group .

The 8th edition of the mineral classification according to Strunz , which is now outdated, but still in use in some cases, does not yet list the oxybismutomicrolite. It would belong to the mineral class of "oxides and hydroxides" and there to the general division of "oxides with a metal: oxygen ratio = 2: 3 (M ₂ O ₃ and related compounds)", where it might belong together with bariomicrolite (discredited 2010) Hydrokenomikrolith, Bismutomikrolith (discredited 2010 mglw. identical to Oxybismutomikrolith) Fluornatromikrolith , Mikrolith , Natrobistantit , Plumbomikrolith , Stannomikrolith , Stibiomikrolith and Uranmikrolith the "pyrochlore group Mikrolith subgroup" with the system number. IV / C.18 .

The 9th edition of Strunz's mineral systematics, which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), does not yet know the oxybismutomicrolite either. It would be classified in the department of "oxides with the molar ratio metal: oxygen = 1: 2 and comparable". This is further subdivided according to the relative size of the cations involved and the crystal structure, so that the mineral is classified according to its composition and structure in the subsection “With large (± medium-sized) cations; Layers of edge-linked octahedra ”would be found where, together with all representatives of the pyrochlore, microlith, Betafit, Roméit and Elsmoreit groups, the pyrochlore supergroup with the system no. 4.DH.15 would form. Along with Fluorcalciomikrolith, Fluornatromikrolith, Hydrokenomikrolith, Hydroxykenomikrolith, Hydromikrolith, Kenoplumbomikrolith, Oxycalciomikrolith, Oxystannomikrolith would thereby Oxybismutomikrolith (formerly Stannomikrolith ) (formerly and Oxystibiomikrolith Stibiomikrolith ) found in the Mikrolithgruppe.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , does not yet know the oxybismutomicrolite. It would be placed in the class of "oxides and hydroxides" and there in the division of "multiple oxides with Nb, Ta and Ti". Here it would be in the “microlith subgroup; Ta> Nb; (Ta ⁺ Nb) _{> 2} (Ti) “with the system no. 02/08/02 within the subsection of " Multiple oxides with Nb, Ta and Ti with the formula A ₂ (B ₂ O ₆ ) (O, OH, F) ".

Chemism

Seven microprobe analyzes on oxybismutomicrolite from the pegmatite "Solnechnaja" resulted in mean values ​​of 3.45% Na ₂ O; 2.88% CaO; 0.31% MnO; 0.76% PbO; 29.81% Bi ₂ O ₃ ; 0.18% ThO ₂ ; 3.89% TiO ₂ ; 1.77% SnO ₂ ; 4.50% Nb ₂ O ₅ ; 51.08% Ta ₂ O ₅ and 1.17% F [(−O = F), total = 99.31%]. Based on two cations on the B position [(Ta + Ti + Nb + Sn) = 2 apfu], the empirical formula was (Bi _0.79 Na _0.68 Ca _0.32 Mn _0.03 Pb _0.02 □ _0.16 ) _{Σ = 2.00} (Ta _1.42 Ti _0.30 Nb _0.21 Sn _0.07 ) _{Σ = 2.00} O _6.00 (O _0.52 F _0.38 □ _0.10 ) _{Σ = 1.00} , which - based on the nomenclature of the pyrochlore upper group - was simplified to (Bi, Na, Ca) ₂ (Ta, Ti, Nb, Sn) ₂ O ₆ (O, F). In the “microliths” of the “Solnechnaja” pegmatite, there is a continuous mixed crystal between fluorine atomic microlite and oxybismutomicrolite due to the high degree of coupled heterovalent substitution. On the A position, Na ⁺ and, to a lesser extent, Ca ^{2+ are} replaced by Bi ³⁺ , which is simultaneously compensated for by the replacement of F ^- by O ^2– on the Y position and by the scheme ^A (Na , Ca) + ^Y F →  ^A Bi + ^Y O can be expressed.

In an in pegmatite "Scherlovyi" the village Taiginka far from Kyshtym , Chelyabinsk region , Southern Südural , Russia, the representative found Mikrolith subgroup was on the basis of two cations on the B has the empirical formula (Bi position _0.94 Mn _{0 , 25} Ca _0.10 U ⁴⁺ _0.07 Pb _0.04 Sb ³⁺ _0.02 Th _0.02 Na _0.01 K _0.01 Ba _0.01 ) _{Σ = 1.47} (Ta _0.97 Ti _0.69 Nb _0.22 Sn _0.10 W _0.02 ) Σ = _2.00 O _6.53 F _0.23 calculated. It is also oxybismutomicrolite - but this is significantly richer in Bi and poorer in F than oxybismutomicrolite from the pegmatite "Solnechaya". It also has significantly lower contents of Na and Ca, but essential contents of Mn . Like the oxybismutomicrolite from “Solnechaya”, the oxybismutomicrolite from “Scherlovyi” shows a high degree of substitution. a. takes place on the B position with substitution of Ta ⁵⁺ by Ti ⁴⁺ . It can be so high that ratios with Ti ⁴⁺  + Sn ⁴⁺  > Ta ⁵⁺  + Nb ⁵⁺ and Ti ⁴⁺  > Sn ⁴⁺ arise, which would result in the mineral oxybismuth betafite , which has not yet been described .

Within the pyrochlore upper group there are theoretically a multitude of substitution possibilities due to the four different positions to be occupied. Oxybismutomicrolite is the bi-dominant analogue of the Na-dominated oxynatromicrolite, the Sb-dominated oxystibiomicrolite and the Sn-dominated oxystannomicrolite.

The sole element combination Bi-Ti-O, as they refer to the official Oxynatromikrolith formula IMA, has among the currently known minerals (as of 2020) in addition to Oxybismutomikrolith only Bismutotantalit , BiTaO ₄ at. Chemically similar are fluorine atromicrolite, (Na _1.5 Bi _0.5 ) Ta ₂ O ₆ F, the as yet undefined mineral " hydroxynatromicrolite " , (Na, Bi ³⁺ , ◻) ₂ Ta ₂ O ₆ (OH), as well the insufficiently characterized “Bismuthian stibiotantalite”, (Sb, Bi) (Ta, Nb) O ₄ , and “Scheteligite”, (Ca, Fe, Mn, Sb, Bi, Y) ₂ (Ti, Ta, Nb, W) ₂ (O, OH) ₇ .

Crystal structure

Oxybismutomicrolite crystallizes in the cubic crystal system in the space group Fd 3 m (space group no. 227) with the lattice parameter a = 10.4746  Å and eight formula units per unit cell . Oxybismutomicrolite from the pegmatite of “Scherlovyi” in the Urals is completely amorphous at room temperature due to its high content of uranium and thorium .

As with all representatives of the pyrochlore upper group with the ideal formula A ₂ B ₂ O ₆ Y, the crystal structure of the oxybismutomicrolite consists of a three-dimensional framework, which is built up by two different types of metal-oxygen (fluorine) polyhedra . The Ta (O, OH) ₆ - octahedra have common corners and thereby form a perforated framework which contains wide channels in the direction [110]. These channels accept the Bi atoms in the A position and their substituents as well as the O ^2– and F ^- ions. Alternatively, the structure of the oxybismutomicrolite can also be represented as a pseudo skeleton, which consists of distorted hexagonal bipyramids [Bi X ₈ ] ( X  = O and F) with common edges, the Ta atoms sitting in the cavities of the structure.

properties

morphology

Oxybismutomikrolith was only found in its type locality in the form of rough octahedral crystals up to 1 mm in size and isometric grains up to 2 mm in diameter, which sit in an albite - lepidolite - elbaite matrix (albite-lepidolite-elbaite complex). Smaller crystals and grains (<0.2 mm diameter) are homogeneous and monomineral, while most of the larger crystals have a well-defined zoning with zones of bismuth-rich fluorine atomic microlite, which can be easily observed in the backscattered electron image .

physical and chemical properties

The crystals of the oxybismutomicrolite at the type locality are black, the oxybismutomicrolite grains in the pegmatite of "Scherlovyi" in the Urals are dark brown. Their line color , on the other hand, is always gray-white. The surfaces of the opaque oxybismutomicrolite, translucent in thin splinters, show a resin- like sheen , which agrees well with the very high value for light refraction (n = 2.184, calculated). Under the polarizing microscope , the mineral is light gray and isotropic in the reflected light and shows neither internal reflections nor pleochroism, but a very high surface relief.

Oxybismutomicrolite shows no cleavage . Due to its brittleness , however , it breaks like amblygonite , with the fracture surfaces being uneven. The Vickers hardness for oxybismutomicrolite was determined to be VHN ₁₀₀  = 609 kg / mm² (range 551–689 kg / mm², load 100 g, number of measurements n = 5), which corresponds to a Mohs hardness of ≈ 5. Oxybismutomicrolite is therefore one of the medium-hard minerals and, like the reference mineral apatite (hardness 5), can be scratched with a pocket knife. The density for oxybismutomicrolite measured by helium pycnometry is 6.98 g / cm³. From the empirical formula and the volume of the unit cell (determined in the crystal structure analysis on single crystals ), the density for the mineral was calculated to be 7.056 g / cm³.

The mineral is neither (356 nm) (nm 254) in the long wavelength even in the short wavelength light UV a fluorescence . Oxybismutomicrolite is not soluble in cold hydrochloric acid , HCl, or in cold nitric acid , HNO ₃ .

Due to the almost complete absence of uranium and thorium in the chemical composition of the oxybismutomicrolite of the type locality, there are no signs of metamictization . The oxybismutomicrolite of the pegmatite of Scherlovyi in the Urals, on the other hand, is clearly metamictic due to its substantial contents of ThO ₂ (0.85% by weight) and UO ₂ (2.83% by weight).

Education and Locations

As a very rare mineral formation, the oxybismutomicrolite could only be described from two sources so far (as of 2020). The type locality for oxybismutomicrolite is the vein-shaped pegmatite “Solnechnaja” in the pegmatite field “Malkhan” near Krasny Chikoi , approx. 320 km southwest of Chita and 200 km southeast of Ulan-Ude , Transbaikalia region in the federal district of Siberia of the Russian Federation . The Malkhan pegmatite field was discovered in the 1980s and is famous for collection-grade gemstones and tourmalines. It is located on the southern slopes of the Malkhan chain, occupies an area of ​​60 km² and contains more than 300 vein-shaped pegmatites. According to dating with the ⁴⁰ Ar / ³⁹ Ar method , the Malkhan pegmatite field is 128–124  Ma .

The only other location is the granite pegmatite from "Scherlovyi" near the village Taiginka not far from Kyschtym , Chelyabinsk Oblast , Southern Urals , Russia. Locations for Oxybismutomikrolith from Germany , Austria and Switzerland are therefore unknown.

Oxybismutomicrolite was formed during the metasomatic transformation of already solidified parts of a highly specialized granite pegmatite. Since the content of Bi in the important rock-forming minerals of pegmatite is low (3  ppm in quartz, 2–3 ppm in mica and 15 ppm in feldspar) and the pegmatite crystallization spread inwards from the contact, the less developed pegmatite parts solidified lead to a strong accumulation of Bi and other incompatible elements including B , F , Li , Cs , Rb , Bi, Nb, Ta and Sn in a pegmatite residue melt. Very high and variable B ₂ O ₃ and H ₂ O contents of melt and liquid inclusions enclosed in quartz from different parts of several pegmatites document increasing contents of the flux during the development of the pegmatite melt and, in addition, the formation of coexisting high flux aluminosilicate melts and hydro-saline fluids. Such fluids containing a lot of flux then caused an intensive metasomatic transformation of the already solidified parts of the pegmatite and the formation of an albite-lepidolite-elbaite complex with miarolitic cavities . Therefore, the albite lepidolite-Elbait complex a fractional most parts of the Pegmatitkörpers. It contains finely divided accessory Bi, Nb and Ta minerals, wherein the Bi content in Elbait 5000  ppm is reached (0.5%) .

Like many pegmatites in the “Malkhan” pegmatite field, the “Solnechnaja” pegmatite also has a strong LCT signature (with enrichment of lithium , cesium and tantalum) in the sense of Petr Černý and Scott Ercit. One of the specific geochemical features of various pegmatite bodies in the Malkhan field is their bismuth enrichment, which leads to the development of unique bi-mineralization and the formation of primary dispersion aureoles. Regardless of the Bi content of individual minerals, the tourmaline-lepidolite-albite complex around the Miaroles has Bi contents of up to 300 ppm Bi. This leads to the development of different bi-mineralizations in the pegmatites with native bismuth, bismuthinite , bismuthite and tantalo-niobates such as bismuth columbite , bismuth tantalite and representatives of the pyrochlore upper group rich in bismuth.

Typical accompanying minerals of Oxybismutomikroliths on its type locality, a 3 m x 2.5 m x 1.5 m wide miarolithischen cavity are, in addition to quartz, tourmaline, Cleavelandit and lepidolite especially native bismuth, Bismutit , Bismutotantalit, fluorine apatite , fluorite , Fluornatromikrolith, pollucite , Stibiotantalite , topaz , xenotime (Y) and Hf -rich zircon . At a distance of 1–2 m from the miarole, the potassium feldspar pegmatite is intensely albitized and converted into albitite; it contains inclusions of lepidolite, orange-colored Spessartine , topaz and pink-colored beryl (variety Vorobieffit). The coarse-grained albite-lepidolite-elbaite complex is formed in some places in the vicinity of the miarole.

In Granitpegmatit of "Scherlovyi" to the Paragenesis minerals of Oxybismutomikroliths beryl, native bismuth, Bismutocolumbit include Cheralith , fluorapatite, fluorine-Schörl , gahnite , Hercynit , magnetite , manganocolumbite , monazite (Ce) , quartz, rutile , Spessartin, xenotime ( Y) and zircon.

use

Oxybismutomicrolite is of no practical importance due to its rarity.

See also

• Systematics of the minerals
• List of minerals

literature

• Marcelo B. Andrade, Hexiong Yang, Daniel Atencio, Robert T. Downs, Nikita V. Chukanov, Marie-Hélène Lemée-Cailleau, Aba Israel Cohen Persiano, Andrés E. Goeta, Javier Ellena: Hydroxycalciomicrolite, Ca _1.5 Ta ₂ O ₆ ( OH), a new member of the microlite group from Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil . In: Mineralogical Magazine . tape 81 , no. 3 , 2017, p. 555–564 , doi : 10.1180 / minmag.2016.080.116 (English).
• Anatoly V. Kasatkin, Sergey N. Britvin, Igor S. Peretyazhko, Nikita V. Chukanov, Radek Škoda and Atali A. Agakhanov: Oxybismutomicrolite, a new pyrochlore-supergroup mineral from the Malkhan pegmatite field, Central Transbaikalia, Russia . In: Mineralogical Magazine . tape 84 , no. 3 , 2020, p. 444–454 , doi : 10.1180 / mgm.2020.25 (English, https://www.researchgate.net/publication/340462908 researchgate.net [PDF; 746 kB ; accessed on November 27, 2019]).

Web links

• Mineral Atlas: Oxybismutomicrolite (Wiki)
• Oxybismutomicrolite. In: mindat.org. Hudson Institute of Mineralogy, accessed July 12, 2020 . 

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at} Anatoly V. Kasatkin, Sergey N. Britvin, Igor S. Peretyazhko, Nikita V. Chukanov, Radek Škoda and Atali A. Agakhanov: Oxybismutomicrolite, a new pyrochlore-supergroup mineral from the Malkhan pegmatite field, Central Transbaikalia, Russia . In: Mineralogical Magazine . tape 84 , no. 3 , 2020, p. 444–454 , doi : 10.1180 / mgm.2020.25 (English, https://www.researchgate.net/publication/340462908 researchgate.net [PDF; 884 kB ; accessed on July 12, 2020]).
2. ↑ NE Zalashkova, MV Kukharchik: Bismutomicrolite - a new variety of microlite . In: Trudy Inst. Mineral. Geokhim. Crystallokhim. Redkikh Elementov Akad. Nauk SSSR . tape 1 , 1957, pp. 77-79 (Russian).
3. ^ Oleg von Knorring, Mary E. Mrose: Westgrenite and waylandite, two new bismuth minerals from Uganda . In: Geological Society of America, Special Paper . tape 73 , 1963, pp. 256–257 (English, limited preview in Google Book Search).
4. ^ ^{A b} Donald David Hogarth: Classification and nomenclature of the pyrochlore group . In: The American Mineralogist . tape 62 , 1977, pp. 403-410 (English, rruff.info [PDF; 849 kB ; accessed on September 3, 2018]).
5. ↑ ^{a b c d} Daniel Atencio, Marcelo B. Andrade, Andrew G. Christy, Reto Gieré, Pavel M. Kartashov: The Pyrochlore supergroup of minerals: Nomenclature . In: The Canadian Mineralogist . tape 48 , 2010, p. 673–698 , doi : 10.3749 / canmin.48.3.673 (English, rruff.info [PDF; 1,4 MB ; accessed on August 30, 2018]).
6. ^ Andrew G. Christy, Daniel Atencio: Clarification of the status of species in the pyrochlore supergroup . In: Mineralogical Magazine . tape 77 , no. 1 , 2013, p. 13–20 , doi : 10.1180 / minmag.2013.077.1.02 (English, main.jp [PDF; 85 kB ; accessed on August 30, 2018]).
7. ↑ Fan Guang, Ge Xiangkun, Li Guowu, Yu Apeng and Shen Ganfu: Oxynatromicrolite, (Na, Ca, U) ₂ Ta ₂ O ₆ (O, F), a new member of the pyrochlore supergroup from Guanpo, Henan Province, China . In: Mineralogical Magazine . tape 81 , no. 4 , 2017, p. 743–751 , doi : 10.1180 / minmag.2016.080.121 (English).
8. ^ Lee A. Groat, Petr Černý, T. Scott Ercit: Reinstatement of stibiomicrolite as a valid species . In: Geologiska Foreningens i Stockholm Forhandlingar . tape 109 , no. 2 , 1987, pp. 105-109 , doi : 10.1080 / 11035898709453757 (English, researchgate.net [PDF; 316 kB ; accessed on August 30, 2018]).
9. ↑ Atso Vorma, Jaakko Siivola: Sukulaite - Ta ₂ Sn ₂ O ₇ - and wodginite as inclusions in cassiterite in the granite pegmatite in Sukula, Tammela in SW Finland . In: Bulletin de la Commission Géologique de Finlande . No. 229 , 1967, pp. 173-187 (English).
10. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: July 2020. (PDF 3000 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, July 2020, accessed July 12, 2020 .  
11. ↑ ^{a b} Minerals with Bi, Ta, O. In: mindat.org. Hudson Institute of Mineralogy, accessed July 12, 2020 .  
12. ^ Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  222-223 .
13. ↑ ^{a b} Oxybismutomicrolite. In: mindat.org. Hudson Institute of Mineralogy, accessed July 12, 2020 .  
14. ↑ Localities for Oxybismutomicrolite. In: mindat.org. Hudson Institute of Mineralogy, accessed July 12, 2020 .  
15. ↑ Find location list for Oxybismutomikrolith at the Mineralienatlas and at Mindat (accessed on July 12, 2020)
16. ↑ Petr Černý, T. Scott Ercit: The classification of granitic pegmatites revisited . In: The Canadian Mineralogist . tape 43 , 2005, p. 2005–2026 , doi : 10.2113 / gscanmin.43.6.2005 (English, https://www.researchgate.net/publication/238667995 researchgate.net [PDF; 494 kB ; accessed on July 12, 2020]).