Investigations of color center phenomena in Topaz and Quartz through electron spin resonance with reference to optical absorption and nuclear magnetic resonance: Implications for extended mineral applications


  • Darius Greenidge Shizuoka University International Center/ Office for the Promotion of Global Education Programs



Color center, electron spin, nuclear spin, optical absorption, topaz


Optical absorption, electron spin resonance (ESR) and nuclear (NMR) studies of silicate minerals such as quartz and topaz help to reveal the nature of a variety of colors which are derived from defects within the crystal structures involving the presence of impurities, trapped holes, and electrons. The present study was inspired by color changes in cinnabar, which upon exposure to sunlight, turns from vermillion red to black under certain conditions, the solid state physical reasons for which have not yet been described. Smoky and amethyst quartz are also bleached by energy from the Sun; reactions that can be reversed by the process of artificial irradiation and heat treatment. Topaz, the focus of this study, exhibits the imperial yellow variety from Ouro Preto, Brazil, which bleaches upon exposure to high temperatures and gives rise to a pink color if chromium is present as an impurity. For the blue variety of topaz, which arises from the irradiation of colorless topaz to smoky, then heat treating to blue, the crystal chemistry remains undefined. Many color centers found in topaz are believed to have a relationship to the presence of aluminum in tetrahedral sites, also related to trapped hole/electron defects. Although NMR studies have targeted the presence of 27Al with uncertain results, optical absorption and ESR studies show clear connections to the production of electronic defects related to absorbing centers caused by high energy irradiation. ESR studies indicate that significant information can be attained relative to these defects when the magnetic vector is parallel to the c axis of the crystal. This paper begins to shed light on the responsible mechanisms that may define the crystal chemistry in terms of the electronic environment, with particular emphasis on topaz.


Akizuki, M., Hampar, M. S., and Zussman, J. (1979). An explanation of anomalous optical properties of topaz. Mineralogical Magazine, 43, 237-241.

Anthony, J. W., Bideaux, R. A. (1997). Handbook of Mineralogy: Vol. 2 Silica, Silicates. Tucson, Arizona: Mineral Data Publishing,.

Burns, Roger G. (1970). Mineralogical Applications of Crystal Field Theory. London: Cambridge University Press.

Cohen, A. J., Makar, L. N. (1982). Models for color centers in smoky quartz. Physica Status Solidi, (a), 73, 593-596.

Cohen, A. J., Janezic, G. G. (1983). Relationships among trapped hole and trapped electron centers in oxidized soda-silica glasses of high purity. Physica Status Solidi (a), 77, 619-624.

da Costa, G. M., Sabioni, A. C. S., Ferreira, C. M. (2000). Imperial topaz from Ouro Preto, Brazil: Chemical character and thermal behaviour.

Journal of Gemmology, 27, 3, 133-138.

Dexter, D. L. (1956). Absorption of light by atoms in solids. Physical Review, series 2, 101, 48-55.

Dickenson, A. C., and Moore, W. J. (1966). Paramagnetic resonance of metal ions in defect centers in topaz. Physical Chemistry of the Solid State, 1953-1966, Bloomington, Indiana: Indiana University Press.

Greenidge, D. C. (1993). Comparison of thermal bleaching of trapped-hole color centers in topaz and quartz, 153p. Doctoral dissertation, University of Pittsburgh, P.A.

Griffiths, J. H. E., Owen, J., Ward, I. M. (1954). Paramagnetic resonance in neutron-irradiated diamond and smoky quartz. Nature, 173, 439-440.

Griscom, D. I. (1978). Defects and impurities in α quartz and fused silica. The Physics of SiO2 and its Interfaces. In Pantelides, S. (Ed.) New York.: Pergamon Press.

Ikeda, K., Schneider, H. (1992). Crystal-field spectroscopic study of Cr-doped mullite. American Mineralogist, 77, 251-257.

Keppler H. (1992). Crystal field spectra and geochemistry of tansistion metal ions in silicate melts and glasses. American Mineralogist, 77, 62-75.

Keller, P. C. (1983). The Capão topaz deposit, Ouro Preto, Minas Gerais, Brazil. Gems & Gemology, 19, 12-20.

Kozu, W., Ueda, J. (1929). Optical and thermal studies of topaz from Naegi, Japan. Science Report, Tohoku University, series 3, vol. 3, 161-170.

Lax, M. (1955). The influence of lattice vibrations on electronic transitions in solids. Photoconductivity Conference, 1954, 111-145, Wiley, New York.

Marfunin, A. S. (1979). Spectroscopy, Luminescence and Radiation Centers in Minerals. New York : Springer-Verlag.

Mizuno, M., Aoki, Y., Endo, K. Greenidge, D. (2006). Local structure analysis of smoky and colorless topaz using single crystal 27Al NMR. Journal of Physics and Chemistry of Solids, 67, 705-709.

Nassau, K., (1974) The effects of gamma rays on the color of beryl, smoky quartz, amethyst and topaz. Lapidary Journal, 4, 20-22,25-26,36-40.

Nassau, Prescott, B. E. (1975). Blue and brown topaz produced by gamma irradiation. American Mineralogist, 60, 705-709.

Nassau. (1975) Smoky, blue, greenish yellow, and other irradiation-related colors in quartz. Mineralogical Magazine, 41, 319, 301-321

Nassau, (1983). The Physics and Chemistry of Color. New York: Wiley.

O’Brien, M. C. M. (1955). The structure of the colour centers in smoky quartz. Royal Society of London Proceedings, 231 A, 404-441.

Oftedal, I. (1963). The germanium contents of some Norwegian topaz specimens. Norsk Geologisk Tidsskrift, 43, 267-269.

Pacchioni, G., Frigoli, F., Ricci, D., Weil, J. A. (2000). Theoretical description of hole localization in a quartz Al center: The importance of exact electron exchange. Physical Review B, 63, 054102-1-8.

Partlow, D. P., and Cohen, A. J. (1986). Optical studies of biaxial Al-related color centers in smoky quartz. American Mineralogist, 71, 589-598.

Phakey, P. P., Horney, R. B. (1978). On the nature of gown-in defects in topaz. Acta Crystallographica, A 32, 177-182.

Poole, C.P. Jr., and Itzel, J.F. Jr., (1963). Optical reflection spectra of chromia-alumina. Journal of Chemistry and Physics, 39, 12, 3445-3455.

Poole, C. P. Jr. (1964). The optical spectra and color of chromium containing solids. Journal of Physics and Chemistry of Solids, 25, 1169-1182.

Schnadt, R., Schneider, J. (1970). The electronic structure of the trapped hole center in smoky quartz. Physik Der Kondensiterten Materie, 11, 19-42.

Spring M,. Grout R. (2002). The blackening of vermilion: An analytical study of the process in paintings. National Gallery Technical Bulletin, 23, 50-61.

Taran, M. N., Langer, K., Platonov, A. N., Indutny, A. N. (1994). Optical absorption Investigation of Cr3+ ion-bearing minerals in the temperature range 77 – 797 K. Physics and Chemistry of Minerals, 21, 360-372.

Taylor, A. L., Farnell, G. W. (1964). Spin lattice interaction experiments on color centers in quartz. Canadian Journal of Physics, 42, 595-607.

Weeks, R. A. (1963). Paramagnetic spectra of E'2 centers in crystalline quartz. Physical Review, 130, 570-576.

Weeks, R. A. (1970). Paramagnetic resonance and optical absorption in gamma-ray irradiated alpha quartz: The Al-center. Journal of the American Ceramics Society, 53, 176-179.

Whittaker, E. J. W., Muntus, R. (1970). Ionic radii for use in geochemistry. Geochimica et Cosmochimica Acta, 9, 279-289.

Xue, X., Kanzaki M., Fukui, H. (2010). Unique crystal chemistry of two polymorphs of topaz-OH: A multi-nuclear NMR and Raman study. American Mineralogist, 95, 1276-1293.