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Columbite
General
CategoryOxide minerals
Formula
(repeating unit)		(FeII,MnII)Nb2O6, or in oxide formula (FeII,MnII)O·Nb2O5
IMA symbolClb[1]
Strunz classification4.DB.35
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPbcn
Identification
ColorBlack, brownish black.
Crystal habitMassive – Granular – Common texture observed in granite and other igneous rock; Striated - Parallel lines on crystal surface or cleavage face.
Cleavage[010] Distinct
FractureSub Conchoidal: Fractures developed in brittle materials characterized by semi-curving surfaces.
Mohs scale hardness6
LusterSub-metallic
StreakBlackish brown
Specific gravity5.3–7.3, Average = 6.3
Optical propertiesBiaxial (+), b = 2.29–2.4
Other characteristics Radioactive, non-fluorescent.
References[2][3][4] [5]

Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of (FeII,MnII)Nb2O6, is a black mineral group that is an ore of niobium. It has a submetallic luster, a high density, and is a niobate of iron and manganese. Niobite has many applications in areospace, construction and the medical industry. Dating columbite minerals is primarily completed by uranium lead (U-Pb) dating which is a time-consuming process.

Columbite has the same composition and crystal symmetry (orthorhombic) as tantalite.[6] In fact, the two are often grouped together as a semi-singular mineral series called columbite-tantalite or coltan in many mineral guides. However, tantalite has a much greater specific gravity than columbite, more than 8.0 compared to columbite's 5.2.[7] The formation of Columbite is dependant on the concentrations of metals present which effect the crystalline structure of the mineral and the environmental impact.

Columbite is also very similar to tapiolite. These minerals have the same chemical composition but different crystal symmetry: orthorhombic for columbite and tetragonal for tapiolite.[8] The largest documented single crystal of columbite consisted of plates 6 mm (0.24 in) thick measuring 76 cm × 61 cm (30 in × 24 in).[9]

Columbite contains varying amounts of thorium and uranium, which makes it radioactive to various degrees.[10] Coltan, a tantalum dominate species of columbite, is often mined artesian and small scale miners which results environmental risks and danger to human health due to unregulated working conditions.

History and etymology[edit]

This mineral group was first found in Haddam, Connecticut, in the United States.[11] The occurrence of columbite in the United States was made known from a specimen presumably stemming from John Winthrop (1606–1676), first Governor of the Connecticut Colony and avid mineral collector. Amidst 600 other samples, it was donated by his namesake and grandson, John Winthrop (1681–1747) to Hans Sloane, President of the Royal Society of London, upon becoming a Fellow of the Royal Society in 1737.[12]

In 1801, Charles Hatchett discovered the element niobium in this specimen,[13] which he named columbium in honour of explorer Christopher Columbus.[14]

Columbite species[edit]

Yttrocolumbite; a species of columbite

Columbite forms opaque crystals that are black to dark brown in colour.[15] The formation of the crystals vary based on the species present in Columbite.

Columbite forms a series with the tantalum-dominant analogue ferrotantalite and one with the manganese-dominant analogue manganocolumbite. Manganocolumbite has a chemical formula of (Mn, Fe)(Nb, Ta)2O6 and often contains small concentrations of tantalum and iron. In addition, manganocolumbite, is often found in pegmatites which are course-grained igneous rocks.[15]

Ferrocolumbite; a species of columbite

The iron-rich member of the columbite group is ferrocolumbite, has a chemical formula of FeNb2O6 and small concentrations of tin and tungsten may be present in the mineral. This species of columbite is often found in pegmatites which as course-grained igneous rocks.[15]

Yttrocolumbite is the yttrium-rich columbite with the formula (Y,U,Fe)(Nb,Ta)O
4, is a radioactive mineral found in Mozambique.[16] This mineral forms due to pegmatites and rare-metal granites.[15]

Structure[edit]

Columbite atoms form an octahedral structure where niobium or tantalum atoms surround an oxygen atom. Overall, Columbite forms orthorhombic crystals which give approximate lengths of the crystal axes as a ≈ 14.27, b ≈ 5.73, and c ≈ 5.06 Å.[17] Different columbite species such as manganocolumbite or ferrocolumbite can change the lengths of the crystal axes.[17]

Face centered crystal structure of columbite (orthorhombic)

Since columbite can form species with other minerals, the physical properties of the mineral can change. When ferrocolumbite is introduced to heat, an equal expansion of the ‘a’ and ‘b’ axis occurs.[17] In addition, due to the size of the ions and the overall structure, ferrocolumbite is more compressible than manganocolumbite.[17] When manganocolumbite is introduced to heat, an expansion of the ‘a’ axis occurs resulting in an uneven change to the structure.[17]

Applications[edit]

When niobite is extracted from columbite, in the ore refining process, applications can be observed in the aerospace, construction, and medical industry.[18] In the aerospace industry, super alloys can be created. Super alloys from niobite create a low mass, and high resistance material often used in spacecrafts.[18] In construction, some high-strength low-alloy (HSLA) steal is created from niobite.[18] In addition, niobite extracted from columbite can be used to create electronic components used in medical equipment such as magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR).[18]

Formation[edit]

Columbite is often found in pegmatite and alluvial deposits, as well as granitic rocks.[19] Columbite minerals are mainly composed of magnesium, iron, niobium, and tantalum where trace amounts of tin, titanium, and scandium have been observed.[19] The overall composition of columbite influences the crystalline structure resulting in different formation processes. Currently, there are two prominent theories for the formation of columbite. One theory was developed due to a strong attraction of niobium and tantalum, within columbite, to silicate melts found in the earth's crust or mantle.[20] In addition, the presence of magma forms columbite by undergoing two crystallization processes.[15] The first crystallization process creates a niobium core and the second crystallization process creates a tantalum rim.[15] This theory is prominent due to the texture of the mineral during the fluid stage, and the magmatic fractional crystallization that occurs during formation.[20] Another prominent theory of the formation of niobium and tantalum, in Columbite minerals, occurs due to hydrothermal fluids.[20] This theory suggests that hydrothermal fluids interact with columbite during formation and as a result irregular crystals are formed.[15]

It is possible that both theories work in conjunction with one another to form columbite minerals as well as different species of columbite such as mangancolumbite, ferrocolumbite, and yttrocolumbite.

Environmental impact[edit]

Columbite minerals have the potential to be radioactive due to trace amounts of uranium and thorium. Radioactive minerals are unstable due to the emission of radiation which causes negative impacts to the environment and human health. Each country has different laws regarding the transportation of radioactive material.[21]

When mining columbite, contamination of ground and surface water are a concern due to the presence of heavy metals in waste rock. In addition, waste rock can lead to acid mine drainage which can affect ground and surface water.[21] To obtain pure columbite, a large quantity of waste rock is produced, leading to negative impacts to the surrounding environment.[21]

During the extraction of niobite or tantalum from columbite, strong acids at high temperatures are used that have negative impacts to the environment. Hydrofluoric acid and sulfuric acid are used in the ore refining processes between temperatures of 250-300oC.[22] These acids can cause soil acidification, air pollution, and water pollution that, in turn, affects ecosystems. Current technology, in the ore refining of columbite, is not selective which leads to impurities present in refined Columbite samples.[22] To remove impurities, a greater concentration of acid is required, leading to a greater potential of environmental hazards.[23]

Dating[edit]

There are three applications to dating columbite group minerals each with advantages and disadvantages. These methods are uranium lead (U-Pb) dating, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). The U-Pb method, can determine the location, and age of a columbite mineral group by the U/Pb ratio.[24][25] This method is often paired with isotope dilution-thermal ionization mass spectrometry (ID-TIMS) to increase precision.[24][25] The LA-ICP-MS method is used in situ to date columbite-tantalite minerals with less than five percent error on the isotopic ratio of uranium and lead.[25] The SIMS method has a high spatial resolution and has a high accuracy in measuring lead isotopes in columbite minerals.[25] The LA-ICP-MS and SIMS method are not commonly used due to the lack of certified reference material.[25]

Artesian and small scale mining[edit]

Artesian and small-scale mining provides jobs for millions of people but typically has negative impacts to human health and the environment.[26] This type of mining is executed by small groups of people, typically under a larger mining cooperation, with simple extraction equipment.[27] This simple extraction equipment can include pickaxes, shovels, basins, and minimal heavy machinery.[27] Coltan, the tantalum dominant species of columbite, is often mined artisanal due to its vast applications in electronics.[28] Artesian and small-scale mining of materials are common in regions such as Africa, Asia, Oceania, Central American, and South America.[27] While this type of mining is important for local economies and livelihood, it is often unregulated which leads to illegal mining and unsafe working conditions. Due to unregulated conditions, the mistreatment of artisanal miners, violence, illegal trading, and sometimes child labour can occur.[27] In addition, long term health effects are common when mining coltan due to the presence of radioactive material within the mineral.[26] In countries such as Sierra Leone, Liberia, and Democratic Republic of Congo lucrative trading of minerals, such as coltan, has occurred due to lack of state control of artesian and small-scale mining in the area.[27]

Further reading[edit]

See also[edit]


References[edit]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mineralienatlas
  3. ^ Columbite-(Fe) Mineral Data
  4. ^ Columbite-(Fe) on Mindat.org
  5. ^ Dampare, S. B.; Nyarko, B. J. B.; Osae, S.; Akaho, E. H. K.; Asiedu, D. K.; Serfor-Armah, Y.; Nude, P. (2005). "Simultaneous determination of tantalum, niobium, thorium and uranium in placer columbite-tantalite deposits from the Akim Oda District of Ghana by epithermal instrumental neutron activation analysis". Journal of Radioanalytical and Nuclear Chemistry. 265: 53–59. doi:10.1007/s10967-005-0860-0. S2CID 97891922.
  6. ^ Chukanov, Nikita V.; Pasero, Marco; Aksenov, Sergey M.; Britvin, Sergey N.; Zubkova, Natalia V.; Yike, Li; Witzke, Thomas (2022-09-08). "Columbite supergroup of minerals: nomenclature and classification". Mineralogical Magazine. 87 (1): 18–33. doi:10.1180/mgm.2022.105. ISSN 0026-461X. S2CID 252172669.
  7. ^ mindat.org Tantalite
  8. ^ P. Cerny et al. "The tantalite-tapiolite gap: natural assemblages versus experimental data" Canadian Mineralogist 30 (1992) 587 free download
  9. ^ P. C. Rickwood (1981). "The largest crystals" (PDF). American Mineralogist. 66: 885–907.
  10. ^ "Simultaneous determination of tantalum, niobium, thorium and uranium in placer columbite-tantalite deposits from the Akim Oda District of Ghana by epithermal instrumental neutron activation analysis". Retrieved 2021-02-02.
  11. ^ Smith, Edgar F. (1905). "Observations on Columbium and Tantalum". Proceedings of the American Philosophical Society. 44 (180): 151–158. ISSN 0003-049X. JSTOR 983511.
  12. ^ Winthrop, John (1844). Silliman, Benjamin (ed.). "Art. V. Selections from an Ancient Catalogue of objects of Natural History, formed in New England more than one hundred years ago". The Amer. J. Science and Arts 47. New Haven: Baldwin, Cradock, and Joy. p. 282. Retrieved 12 February 2015. ... (p.282:) Mr. Winthrop was grandson of the first governor of Connecticut, great grandson of the first governor of Massachusetts ... (p.290:) A black mineral ... Is this the Columbite? ... it appeared that it had been sent ... to Sir Hans Sloane, by Mr. Winthrop of Massachusetts. ...'
  13. ^ Griffith, William P.; Morris, Peter J.T. (22 September 2003). "Charles Hatchett FRS (1765–1847), Chemist and Discoverer of Niobium" (PDF). Notes and Records of the Royal Society of London. 57 (3). London: The Royal Society Publishing: 359. doi:10.1098/rsnr.2003.0216. S2CID 144857368. Retrieved 12 February 2015. ... In 1800–01, while he was arranging some minerals at the British Museum in Bloomsbury, he became particularly interested in a specimen which was described in Sir Hans Sloane's catalogue of the 'Metalls', no. 2029 from his collection, as 'a very heavy black stone with golden streaks ... from Nautneague. From Mr. Winthrop' ... The donor was probably John Winthrop (1681–1747), a great-grandson of the founder of Massachusetts Bay colony. When Winthrop was elected FRS in 1734 he gave Sir Hans Sloane, then President of the Society, a collection of about 600 minerals. ...'
  14. ^ Jameson, Robert (1805). System of Mineralogy, Vol. II. Edinburgh: Bell and Bradfute (et al.). p. 582. Retrieved 15 February 2015. ... Mr Hatchett found it to contain a metal, which, from its properties, could not be referred to any hitherto known; hence he was of opinion that it should be considered as a new genus, to which he gave the name Columbium, in honour of the discoverer of America. ...'
  15. ^ a b c d e f g Siachoque, Astrid; Garcia, Rodolfo; Vlach, Silvio R.F. (2020-05-04). "Occurrence and Composition of Columbite-(Fe) In the Reduced A-Type Desemborque Pluton, Graciosa Province (S-SE Brazil)". Minerals. 10 (5): 411. Bibcode:2020Mine...10..411S. doi:10.3390/min10050411. ISSN 2075-163X.
  16. ^ Abdel Gawad, Ahmed E.; Ali, Khaled; Eliwa, Hassan; Sayyed, M. I.; Khandaker, Mayeen Uddin; Bradley, David A.; Osman, Hamid; Elesawy, Basem H.; Hanfi, Mohamed Y. (2021-12-07). "Radiological Investigation on Sediments: A Case Study of Wadi Rod Elsayalla the Southeastern Desert of Egypt". Applied Sciences. 11 (24): 11884. doi:10.3390/app112411884. ISSN 2076-3417.
  17. ^ a b c d e Balassone, Giuseppina; Danisi, Rosa Micaela; Armbruster, Thomas; Altomare, Angela; Moliterni, Anna Grazia; Petti, Carmela; Mondillo, Nicola; Ghiara, Maria Rosaria; Saviano, Michele (2015-07-01). "An insight into crystal chemistry and cation order of columbite-(Fe) and columbite-(Mn) from worldwide occurrences". Neues Jahrbuch für Mineralogie - Abhandlungen. 192 (3): 275–287. doi:10.1127/njma/2015/0285. ISSN 0077-7757.
  18. ^ a b c d Sanchez-Segado, Sergio; Monti, Tamara; Katrib, Juliano; Kingman, Samuel; Dodds, Chris; Jha, Animesh (2017-12-21). "Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase". Scientific Reports. 7 (1): 18016. Bibcode:2017NatSR...718016S. doi:10.1038/s41598-017-18272-3. ISSN 2045-2322.
  19. ^ a b Wise, Michael A.; Brown, Cathleen D. (2011-12-01). "Chemical composition of coexisting columbite-group minerals and cassiterite from the Black Mountain pegmatite, Maine". European Journal of Mineralogy. 23 (5): 817–828. Bibcode:2011EJMin..23..817W. doi:10.1127/0935-1221/2011/0023-2102. ISSN 0935-1221.
  20. ^ a b c Zuo, Yushan; Gao, Zhengxi; Zuo, Lei; Zhang, Peng; Liu, Rui; Zhang, Qing; Zhang, Tingting (2022-12-03). Yang, Fan (ed.). "Ultrastructure of a Columbite-Tantalite Mineral from the Zhaojinggou Ta-Nb Deposit in the North China Craton: Direct Evidence of the Formation Mechanism of the Columbite-Group Minerals". Geofluids. 2022: 1–9. doi:10.1155/2022/8125419. ISSN 1468-8123.
  21. ^ a b c Isah, Mohammed Engha; Abdulmumin, Nuhu Abdulkadir; Elaoyi, Paul D.; Audu, Ephraim (December 2019). "Effects of columbite/tantalite (COLTAN) mining activities on water quality in Edege-Mbeki mining district of Nasarawa state, North Central Nigeria". Bulletin of the National Research Centre. 43 (1). doi:10.1186/s42269-019-0237-0. ISSN 2522-8307.
  22. ^ a b Sanchez-Segado, Sergio; Monti, Tamara; Katrib, Juliano; Kingman, Samuel; Dodds, Chris; Jha, Animesh (2017-12-21). "Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase". Scientific Reports. 7 (1): 18016. Bibcode:2017NatSR...718016S. doi:10.1038/s41598-017-18272-3. ISSN 2045-2322.
  23. ^ Baba, Alafara Abdullahi; Jacob, Sunday O.; Olaoluwa, Daud T.; Abubakar, Abdulrahman; Womiloju, Adeola O.; Olasinde, Fausat T.; Abdulkareem, Aishat Y. (2018-04-23). "Processing of a Nigerian columbite-rich ilmenite ore for improved industrial application by sulphuric acid solution". Indonesian Mining Journal. 21 (1): 9–19. doi:10.30556/imj.Vol21.No1.2018.674. ISSN 2527-8797.
  24. ^ a b Tapster, Simon; Bright, Joshua W. G. (2020-12-18). "High-precision ID-TIMS cassiterite U–Pb systematics using a low-contamination hydrothermal decomposition: implications for LA-ICP-MS and ore deposit geochronology". Geochronology. 2 (2): 425–441. Bibcode:2020GeChr...2..425T. doi:10.5194/gchron-2-425-2020. ISSN 2628-3697.
  25. ^ a b c d e Feng, Yonggang; Liang, Ting; Zhang, Ze; Wang, Yiqian; Zhou, Yi; Yang, Xiuqing; Gao, Jinggang; Wang, Hui; Ding, Kun (August 2019). "Columbite U-Pb Geochronology of Kalu'an Lithium Pegmatites in Northern Xinjiang, China: Implications for Genesis and Emplacement History of Rare-Element Pegmatites". Minerals. 9 (8): 456. Bibcode:2019Mine....9..456F. doi:10.3390/min9080456. ISSN 2075-163X.
  26. ^ a b Akiwumi, Fenda A.; Hollist, Arthur O. (April 2016). "The new kid on the old block: Coltan, conflict-prone minerals, and post-war reconstruction in Sierra Leone". The Extractive Industries and Society. 3 (2): 316–319. doi:10.1016/j.exis.2015.06.002.
  27. ^ a b c d e Rodríguez-Novoa, Felipe; Holley, Elizabeth (January 2023). "Coexistence between large-scale mining (LSM) and artisanal and small-scale mining (ASM) in Perú and Colombia". Resources Policy. 80: 103162. Bibcode:2023RePol..8003162R. doi:10.1016/j.resourpol.2022.103162. ISSN 0301-4207.
  28. ^ "Artisanal and Small-Scale Mining", Breaking New Ground, Routledge, pp. 313–334, 2016-12-05, doi:10.4324/9781315541501-17, ISBN 978-1-315-54150-1, retrieved 2024-04-06

External links[edit]


source: https://en.wikipedia.org/wiki/Ferrocolumbite

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