Crystallochemical studies on davidite from Bichun, Jaipur District, Rajasthan, India

  • Yamuna Singh
  • Anubhooti Saxena
  • A K Bhatt
  • R Viswanathan
  • T S Shaji
  • L K Nanda


Crystallochemical data on metamict davidite from albitites and albitised rocks from the Bichun area (Jaipur district, Rajasthan, India) of Banded Gneissic Complex (BGC) are provided. Davidite occurs as euhedral, subhedral to anhedral crystals in the form of disseminated grains and also as fracture filled veins. The crystals of davidite are up to 8 cm in length and 6 cm in width. The powder X-ray diffraction (XRD) pattern of the heat-treated davidite (at \(900{^{\circ }}\hbox {C}\)) reveals well-defined reflections of crystallographic planes. The calculated unit-cell parameters of the heat treated davidite are: \(\hbox {a}_{0} = \hbox {b}_{0} = 10.3556 \, \text {\AA }\) and \(\hbox {c}_{0} = 20.9067 \, \text {\AA }\), with unit-cell volume \(\hbox {(V)} = 1941.6385 \, \text {\AA }^{3}\); and \({\upalpha }={\upbeta }= 90^{\circ }\) and \({\upgamma }= 120^{\circ }\), which are in agreement with the values of davidite standard. Geochemical data reveals that the investigated davidite contains 51.5–52.6% \(\hbox {TiO}_{2}\), 14.8–15.1% \(\hbox {Fe}_{2} \hbox {O}_{3}\), 9.8–10.2% FeO, 6.97–7.12% \(\hbox {U}_{3} \hbox {O}_{8}\), 6.72–6.92% \(\hbox {RE}_{2} \hbox {O}_{3}\), 3.85–3.61% \(\hbox {K}_{2}\hbox {O}\), 0.9–1.4% \(\hbox {Al}_{2} \hbox {O}_{3}\), and 0.8–1.2% \(\hbox {SiO}_{2}\). The calculated structural formulae of the two davidite crystals are: D-1: \(\hbox {K}_{0.0044/0.004} \hbox {Ba}_{0.0044/0.005} \hbox {Ca}_{0.20/0.20} \hbox {Na}_{0.012/0.012} \hbox {Mn}_{0.053/0.053} \hbox {Mg}_{0.14/0.14} \hbox {Pb}_{0.0076/0.008} \hbox {Fe}_{2.675/2.675} \hbox {Fe}_{1.59/1.59} \hbox {Y}_{0.1175/0.118} \hbox {P}_{0.053/0.053} \hbox {Nb}_{0.008/0.008} \hbox {Sn}_{0.001/0.001} \hbox {Zr}_{0.033/0.033} \hbox {U}_{0.468/0.468} \hbox {Th}_{0.009/0.009} \,\,\hbox {REE}_{0.6829/0.683})_{6.05/6.05} (\hbox {Ti}_{12.15/12.15}\,\, \hbox {Fe}_{1.9022/1.903} \hbox {Si}_{0.372/0.372}\,\, \hbox {Al}_{0.517/0.517}\,\, \hbox {Cr}_{0.018/0.018} \hbox {Co}_{0.009/0.009} \hbox {Ni}_{0.027/0.027})_{15/15} \hbox {O}_{36/36} (\hbox {OH}_{0.319/0.319[]1.681/1.681})_{2/2}\) and D-2: \((\hbox {K}_{0.004/0.004} \hbox {Ba}_{0.005/0.005} \hbox {Ca}_{0.20/0.20} \hbox {Na}_{0.012/0.012} \hbox {Mn}_{0.05/0.05} \hbox {Mg}_{0.094/0.094} \hbox {Pb}_{0.007/0.007} \hbox {Fe}_{2.58/2.58} \hbox {Fe}_{1.71/1.71} \hbox {Y}_{0.112/0.112} \hbox {P}_{0.106/0.106} \hbox {Nb}_{0.006/0.006} \hbox {Sn}_{0.001/0.001} \hbox {Zr}_{0.03/0.03} \hbox {U}_{0.48/0.48} \hbox {Th}_{0.009/0.009} \hbox {REE}_{0.665/0.665})_{6.088/6.088} (\hbox {Ti}_{12.48/12.48} \hbox {Fe}_{1.87/1.87} \hbox {Si}_{0.249/0.249} \hbox {Al}_{0.334/0.334} \hbox {Cr}_{0.019/0.019} \hbox {Co}_{0.008/0.008} \hbox {Ni}_{0.04/0.04})_{15/15} \hbox {O}_{36/36} (\hbox {OH}_{0.098/0.098[]1.90/1.90})_{2/2}\). The calculated structural formulae are not fully stoichiometric, which could be due to metamict nature of davidite. The characteristic feature of distribution pattern of REE in davidite is unusually high concentration of LREE and HREE and substantially low content of MREE. It may be due to the occupation of REEs in two distinct crystallographic sites in davidite structure, i.e., M(1) and M(O) sites. Chondrite-normalised plot of davidite reveals a pronounced negative Eu-anomaly (\(\hbox {Eu}/\hbox {Eu}^{*} = 0.30{-}0.39\)), which suggests extremely fractionated nature of the metasomatising fluids from which davidite had crystallized. Metamict davidite-bearing U ores not only from Rajasthan, but also from other parts of India are likely to yield very high U leachability, thereby making them attractive sources of U, which otherwise are ignored by mineral engineers as uneconomic U ores.


Mineralogy mineral chemistry XRD pattern metamict davidite Bichun Jaipur Rajasthan India 



The authors express their sincere gratitude to the Chemistry Group, AMD, Hyderabad, for analytical support and to Prof. N V Chalapathi Rao and two anonymous reviewers of the journal for their insightful reviews and useful suggestions.


  1. Boynton W V 1984 Geochemistry of the rare earth elements: Meteorite studies; In: Rare earth element geochemistry: Developments in geochemistry (ed.) Henderson P, Elsevier, Amsterdam, 2 63–114.Google Scholar
  2. Cuney M and Kyser K 2008 Recent and not-so-recent developments in uranium deposits and implications for exploration; Mineral. Assoc. Canada, Short Course Series 39 97–113.Google Scholar
  3. Dixon P and Wylie A W 1951 An unusual distribution of the lanthanons; Nature 167 526.CrossRefGoogle Scholar
  4. Ellsworth H V 1932 Rare-earth element minerals of Canada; Can. Geol. Survey, Econ. Geol. Ser. 11.Google Scholar
  5. Gaines R V, Skinner H C W, Foord E E, Mason and Rosenzweig A 1997 Dana’s New Mineralogy; 8th edn, John Wiley & Sons, Inc., 1819p.Google Scholar
  6. Gatehouse B M, Grey I E and Kelly P R 1979 The crystal structure of davidite; Am. Mineral 64 1010–1017.Google Scholar
  7. Heinrich E Wm 1958 Mineralogy and geology of radioactive raw materials; McGraw Hill Book Company Inc., New York, 654p.Google Scholar
  8. Heron A M 1953 Geology of Central Rajputana; Geol. Surv. India Memoir 79(1) 1–389.Google Scholar
  9. Jain R B, Yadav O P, Rahman M, Thippeswamy S, Fahmi S, Sharma D K and Singh G 1999 Petrography and geochemistry of the radioactive albitites and their genesis, Moanda area, north Rajasthan; J. Geol. Soc. India 53(4) 407–415.Google Scholar
  10. Jayalal 2008 Preliminary assessment of pegmatite for rare earth and rare metals in parts of Ajmer, Udaipur, Bhilwara and Pali districts, Rajasthan; Rec. Geol. Surv. India 140 38–39.Google Scholar
  11. Latha A, Parihar P S, Shiv Kumar K and Nayak K 2015 Understanding U-mineralisation at Bichun–Nayagaon, Jaipur district, Rajasthan – A petrological approach; J. Appl. Geochem. 17(4) 416–420.Google Scholar
  12. Neumann H and Sverdrup T L 1960 Davidite from Tuftan, Iveland; Norsk Geol. Tidsskr. 40 277–288.Google Scholar
  13. Pabst A 1961 X-ray crystallography of davidite; Am. Mineral. 46 700–718.Google Scholar
  14. Ray S K 1990 The albitite line of northern Rajasthan – A fossil intracontinental rift zone; J. Geol. Soc. India 36 413–423.Google Scholar
  15. Shaji T S, Nautiyal K, Yadav G S, Yadav O P, Nanda L K and Maithani P B 2011 Occurrence of metamict davidite, brannerite and uraninite bearing albitite and albitised gneisses in the Banded Gneissic Complex around Bichun and Nayagaon areas, Jaipur district, Rajasthan India; Expl. Res. Atomic Minerals 21 21–26.Google Scholar
  16. Singh G, Singh R, Sharma D K, Yadav O P and Jain R B 1998 Uranium and REE potential of the albitite–pyroxenite–microclinite belt of Rajasthan; Expl. Res. Atomic Minerals 11 1–12.Google Scholar
  17. Singh Y, Viswanathan R, Parihar P S and Maithani P B 2012 Uranium, multiple oxide, thorium, yttrium and rare earth element mineral occurrences identified by X-ray diffractometry in and around albitite belt of western India: Significance for ore genesis and beneficiation; Gondwana Geol. Mag., Spec. Vol. 13 53–70.Google Scholar
  18. Singh Y, Viswanathan R, Parihar P S and Maithani P B 2013 X-ray crystallography of uraninites associated with the albitite belt of western India: Evidence for the high-temperature origin of uranium and associated mineralization; J. Geol. Soc. India 81(1) 79–90.CrossRefGoogle Scholar
  19. Sinha-Roy S, Malhotra G and Mohanty M 1998 Geology of Rajasthan; Geol. Soc. India, Bangalore, pp. 127–152.Google Scholar
  20. Sinha D K, Fahmi S, Bhatt A K, Singh G and Singh R 2000 Evidences for soda metasomatism in Ladera–Sakhum areas, northeastern Rajasthan, India; J. Geol. Soc. India 56 573–582.Google Scholar
  21. Yadav O P, Hamilton S, Vimal R, Saxena S K, Pande A K and Gupta K R 2002 Metasomatite and albitite related uranium mineralisation in Rajasthan; Expl. Res. Atomic Minerals 14 109–130.Google Scholar
  22. Yadav O P, Saxena S K, Pande A K and Gupta K R 2004 Sodic metasomatism – a feature of tectonomagmatic activation in Khetri sub-basin, Rajasthan, India; Geol. Surv. India, Spec. Publ. 72 301–312.Google Scholar
  23. Yang C L 2008 Progressive albitisation in the ‘Migmatite Creek’ region Weekeroo Inlier, Curnamona. Thesis submitted to School of Earth and Environmental Sciences, University of Adelaide.Google Scholar

Copyright information

© Indian Academy of Sciences 2018

Authors and Affiliations

  • Yamuna Singh
    • 1
  • Anubhooti Saxena
    • 2
  • A K Bhatt
    • 3
  • R Viswanathan
    • 1
  • T S Shaji
    • 4
  • L K Nanda
    • 1
  1. 1.Atomic Minerals Directorate for Exploration and Research, Department of Atomic EnergyGovernment of IndiaHyderabadIndia
  2. 2.Atomic Minerals Directorate for Exploration and Research, Department of Atomic EnergyGovernment of IndiaJaipurIndia
  3. 3.Atomic Minerals Directorate for Exploration and Research, Department of Atomic EnergyGovernment of IndiaBangaloreIndia
  4. 4.Atomic Minerals Directorate for Exploration and Research, Department of Atomic EnergyGovernment of IndiaThiruvananthapuramIndia

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