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. 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]

History and etymology

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

Columbite forms a series with the tantalum-dominant analogue ferrotantalite and one with the manganese-dominant analogue manganocolumbite. The iron-rich member of the columbite group (ferrocolumbite) often contains some tin and tungsten. Yttrocolumbite is the yttrium-rich columbite with the formula (Y,U,Fe)(Nb,Ta)O
4, is a radioactive mineral found in Mozambique.[15]

Formation

Columbite is often found in pegmatite and alluvial deposits, granitic rocks.[16]

Dating

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.[17][18] This method is often paired with isotope dilution-thermal ionization mass spectrometry (ID-TIMS) to increase precision.[17][18] 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.[18] The SIMS method has a high spatial resolution and has a high accuracy in measuring lead isotopes in columbite minerals.[18] The LA-ICP-MS and SIMS method are not commonly used due to the lack of certified reference material.[18]

Further reading

See also

References

  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. ^ 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.
  16. ^ 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.
  17. ^ 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.
  18. ^ 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.

External links

Wikimedia Commons has media related to Columbite.


Manganese minerals
Ore minerals, mineral mixtures and ore deposits
Authority control databases: National
Categories