Skip to main content

Advertisement

Log in

Optical spectroscopic study of synthetic NaScSi2O6–CaNiSi2O6 pyroxenes at normal and high pressures

  • Original Paper
  • Published:
Physics and Chemistry of Minerals Aims and scope Submit manuscript

Abstract

Six synthetic NaScSi2O6–CaNiSi2O6 pyroxenes were studied by optical absorption spectroscopy. Five of them of intermediate (Na1−x , Ca x )(Sc1−x , Ni x )Si2O6 compositions show spectra typical of Ni2+ in octahedral coordination, more precise Ni2+ at the M1 site of the pyroxene structure. The common feature of all spectra is three broad absorption bands with maxima around 8,000, 13,000 and 24,000 cm−1 assigned to 3 A 2g → 3 T 2g, 3 A 2g → 3 T 1g and →3 T 1g (3 P) electronic spin-allowed transitions of VINi2+. A weak narrow peak at ∼14,400 cm−1 is assigned to the spin-forbidden 3 A 2g → 1 T 2g (1 D) transition of Ni2+. Under pressure the spin-allowed bands shift to higher energies and change in intensity. The octahedral compression modulus, \( k^{{{\text{loc}}}}_{{{\text{Ni}}{\left( {{\text{M}}1} \right)}}} , \) calculated from the shift of the 3 A 2g → 3 T 2g band in the (Na0.7Ca0.3)(Sc0.7Ni0.3)Si2O6 pyroxene is evaluated as 85±20 GPa. The Racah parameter B of Ni2+(M1) is found gradually changing from ∼919 cm−1 at ambient pressure to ∼890 cm−1 at 6.18 GPa. The Ni end-member pyroxene [(Ca0.93 Ni0.07)NiSi2O6] has a spectrum different from all others. In addition to the above mentioned bands of Ni2+(M1) it displays several new relatively intense and broad extra bands, which were attributed to electronic transitions of Ni2+ at the M2 site. In difference to CaO8 polyhedron geometry of an eightfold coordination, Ni2+(M2)O8 polyhedra are assumed to be relatively large distorted octahedra. Due to different distortions and different compressibilities of the M1 and M2 sites the Ni2+(M1)- and Ni2+(M2)-bands display rather different pressure-induced behaviors, becoming more resolved in the high-pressure spectra than in that measured at atmospheric pressure. The octahedral compression modulus of Ni2+(M1) in this end-member pyroxene is evaluated as 150 ± 25 GPa, which is noticeably larger than in Ni0.3 pyroxene. This is due to a smaller size and, thus, a stiffer character of Ni2+(M1)O6 octahedron in the (Ca0.93Ni0.07)NiSi2O6 pyroxene compared to (Na0.7Ca0.3)(Sc0.7Ni0.3)Si2O6.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

Notes

  1. Rossman et al. (1981) found this bands in a variety of complex nickel oxides appearing at ∼720–740 nm (13,500–13,900 cm−1), i.e. at somewhat lower energies than in our case. These differences may be due to different degree of covalence of Ni–O bonds in oxides and pyroxene structures. Note that Ito and Sone (1985) also attributed a band at 721 nm (13,870 cm−1) in spectrum of [Ni(H2O)6]2+ to 3 A 2g → 1 E g transition of Ni2+.

  2. Tejedor-Tejedor et al. (1983) attributed some features in diffuse reflectance spectra of nickel-bearing phyllosilicates to Ni2+ in fourfold coordination replacing Si4+. However, latter this attribution was discriminated by Manceau and Calas (1987), who found “no spectroscopic support of tetrahedrally coordinated Ni in phyllosilicates”.

References

  • Boström D (1987) Single-crystal X-ray diffraction studies of synthetic Ni–Mg olivine solid solution. Am Mineral 72:965–972

    Google Scholar 

  • Brown ID, Shannon RD (1973) Empirical bond-strength–bond-length curves for oxides. Acta Crystallogr A29:266–282

    Google Scholar 

  • Burns RG (1993) Mineralogical applications of crystal field theory, 2nd edn. Cambridge University Press, Cambridge

    Google Scholar 

  • Fukunaga O, Yamaoka S, Endo T, Akaishi M, Kanda H (1979) Modification of belt-like high-pressure apparatus. High Press Sci Technol 1:846–852

    Google Scholar 

  • Garsche M, Langer K (1994) Equilibrium and kinetics of cation distribution in Ni-Mg-olivine from structure refinements and microspectrometry. In: Putnis A (ed) Kinetics processes in minerals and ceramics (MINC). Proceedings of an ESF Workshop on kinetics of cation ordering. Cambridge, 5 pp

  • Ghose S, Wan C, Okamura FP (1987) Crystal structures of CaNiSi2O6 and CaCoSi2O6 and some crystal-chemical relations in C2/c clinopyroxenes. Am Mineral 72:375–381

    Google Scholar 

  • Goldman DS, Rossman GR (1978) Determination of quantitative cation distribution in orthopyroxenes from electronic absorption spectra. Phys Chem Miner 4:43–55

    Article  Google Scholar 

  • Hu X, Langer K, Bostrom D (1990) Polarized electronic absorption spectra and Ni–Mg partitioning in olivines (Mg1−x Ni x )2[SiO4]. Eur J Mineral 2:29–41

    Google Scholar 

  • Ito H, Sone K (1985) On the assignment of band II in the electronic spectrum of [Ni(H2O)6]2+. Bull Chem Soc Jpn 58:2703–2702

    Article  Google Scholar 

  • Langer K (1990) High pressure spectroscopy. In: Monttana A, Burragato F (eds) Absorption spectroscopy in mineralogy. Elsevier, Amsterdam, pp 228–284

  • Langer K (2000) Another look through the microscope—locally resolved electronic absorption spectra of silicate minerals measured in a microscope-spectrometer. J Czech Geol Soc 45:37–62

    Google Scholar 

  • Langer K, Taran MN, Platonov AN (1997) Compression moduli of Cr3+-centered octahedra in a variety of oxygen-based rock-forming minerals. Phys Chem Miner 24:109–114

    Article  Google Scholar 

  • Levien L, Prewitt CT (1981) High-pressure structural study of diopside. Am Mineral 66:315–323

    Google Scholar 

  • Manceau A, Calas G (1987) Absence of evidence for Ni/Si substitution in phyllosilicates. Clay Miner 22:357–362

    Article  Google Scholar 

  • Manceau A, Calas G, Decarreau A (1985) Nickel-bearing clay minerals: 1. Optical spectroscopic study of nickel crystal chemistry. Clay Miner 20:367–387

    Article  Google Scholar 

  • Marfunin AS (1979) Physics of minerals and inorganic materials: an introduction. Springer, Berlin

    Google Scholar 

  • Ohashi H (1988) Unit cell dimensions of the NaScSi2O6–CaNiSi2O6 series pyroxenes formed at atmospheric pressure. J Min Petrol Econ Geol 83:440–442

    Google Scholar 

  • Ohashi H, Osawa T, Kimura M (1997) Immiscibility phenomena in the NaScSi2O6–CaNiSi2O6 pyroxene system at 6 GPa pressure. In: Gupta AK, Onuma K, Arima M (eds) Geochemical studies on synthetic, natural rock systems. Allied Publishers Ltd, New Delhi, pp 42–47

    Google Scholar 

  • Ohashi H, Osawa T, Sato A (1994) Structure of NaScSi2O6. Acta Crystallogr C50:838–840

    Google Scholar 

  • Ohashi H, Osawa T, Sato A (2003) Crystal structures of (Na, Ca)(V, Mn)Si2O6 pyroxenes, In: Ohashi H (ed) X-ray study on Si–O bonding. Maruzen, Tokyo, pp 59–71. ISBN 4-89630-094-7

    Google Scholar 

  • Ottonello G, Della Giusta A, Molin GM (1989) Cation ordering in Ni–Mg olivines. Am Mineral 74:411–421

    Google Scholar 

  • Rossi G, Oberti R, Dal Negro A, Molin GM, Mellini M (1987) Residual electron density at the M2 site in C2/c clinopyroxenes: relationships with bulk chemistry and sub-solidus evolution. Phys Chem Miner 14:514–520

    Article  Google Scholar 

  • Rossman GR, Shannon RD, Warring RK (1981) Origin of the yellow color of complex nickel oxides. J Solid State Chem 39:277–287

    Article  Google Scholar 

  • Shannon RD (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chaleogenides. Acta Crystallogr A32:751–767

    Google Scholar 

  • Solntsev VP, Tsvetkov EG, Alimpiev AI, Mashkovtsev RI (2006) Coordination and valent state of nickel ions in beryl and chrysoberyl crystals. Phys Chem Miner 33:300–313

    Article  Google Scholar 

  • Sviridov DT, Sviridova RK, Smirnov YuF (1976) Optical spectra of transition metal ions in crystals. Nauka, Moscow (in Russian)

  • Taran MN, Langer K (2001) Electronic absorption spectra of Fe2+ ions in oxygen-based rock-forming minerals at temperatures between 297 and 600 K. Phys Chem Miner 28:199–210

    Article  Google Scholar 

  • Taran MN, Langer K (2003) Single-crystal high-pressure electronic absorption spectroscopic study of natural orthopyroxenes. Eur J Mineral 15:689–695

    Article  Google Scholar 

  • Taran MN, Langer K, Platonov AN, Indutny VV (1994) Optical absorption investigation of Cr3+ ion-bearing minerals in the temperature range 77–797 K. Phys Chem Miner 21:360–372

    Article  Google Scholar 

  • Taran MN, Langer K, Geiger CA (2002) Single-crystal electronic absorption spectroscopy of synthetic chromium-, cobalt-, and vanadium-bearing pyropes at different temperatures and pressures. Phys Chem Miner 29:362–368

    Article  Google Scholar 

  • Taran MN, Langer K, Koch-Müller M (2007) Pressure dependence of color of natural uvarovite: the barochromic effect. Phys Chem Miner (in press)

  • Tejedor-Tejedor M.I., Anderson MA, Herbillon AJ (1983) An investigation of the coordination number of Ni2+ in nickel bearing phyllosilicates using diffuse reflectance spectroscopy. J Solid State Chem 50:153–162

    Article  Google Scholar 

  • Tröger VE (1968) Optical identification of rock-forming minerals. Nedra, Moscow (in Russian)

  • White WB, McCarthy GJ, Scheetz BE (1971) Optical spectra of chromium, nickel, and cobalt-containing pyroxenes. Am Mineral 56:72–89

    Google Scholar 

Download references

Acknowledgments

We are thankful to two anonymous reviewers whose comments and suggestions helped to improve the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Michail N. Taran.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Taran, M.N., Ohashi, H. & Koch-Müller, M. Optical spectroscopic study of synthetic NaScSi2O6–CaNiSi2O6 pyroxenes at normal and high pressures. Phys Chem Minerals 35, 117–127 (2008). https://doi.org/10.1007/s00269-007-0202-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00269-007-0202-6

Keywords

Navigation