Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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A study on the identification of turquoise by FT-IR

FT-IR을 이용한 터키석의 감별에 관한 연구

  • Published : 2004.12.01
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Abstract

Inorganic materials, including gemstones, also have characteristic vibrational energies in the infrared that can be used for identification. For infrared spectroscopy, absorptions associated with the vibrations of the crystal structure (lattice vibrations) are characteristic of the given combination of atoms constituting the gemstone. Natural turquoise $CuAl_6(PO_4)_4\cdot(OH)_8\cdot 5H_2O$ can be distinguished easily from its common substitutes in the infrared range 2000~450$\textrm{cm}^{-1}$ by features in the mid-infrared. Gilson turquoise, which is a synthetic, exhibits a significantly smoother pattern when compared with natural turquoise, because of a different state of aggregation. Also, because the natural turquoise and gibbsite are so different chemically, their patterns are very different. The technique, which is infrared spectroscopy, is nondestructive and, with Fourier transform instrumentation, extremely rapid.

보석을 포함한 무기물질은 적외선 영역에서 특성적인 진동 에너지를 가지고 있으며 이를 이용하여 감별에 응용 되기도 한다. 결정격자의 진동과 관련이 있는 적외선 분광기의 흡수 에너지는 보석의 구성원자의 결합과 관련된 특징이다. 천연 터키석[$CuAl_6(PO_4)_4\cdot(OH)_8\cdot 5H_2O$]은 이러한 적외선의 고유한 특성에 의해 2000~450$\textrm{cm}^{-1}$ 중적외선 범위에서 천연 보석에 처리된 터키석과 합성 터키석, 모조 터키석으로부터 감별 할 수 있었다. 합성 Gilson 터키석의 스펙트럼은 천연 터키석과 비교하였을 때 보다 부드러운 스펙트럼이 나타났으며 이는 집합체의 상태가 천연 터키석과 다르기 때문이었다. 또한 천연 터키석과 외관이 매우 유사한 gibbsite는 다른 화학조성을 지니고 있음으로 인해 적외선 스팩트럼 역시 매우 다름을 보여 주었다. 적외선 분광기는 비파괴 검사로서 빠른 분석이 가능하였다.

Keywords

References

  1. R. Webster, 'Gems-their sources, descriptions and identification', 5th ed., PG. Read (Butterworth Heinemann, Oxford, 1994) 254
  2. A.L. Matlins and A.C. Bonanno, 'Gem identification made easy', 2nd ed., AL. Matlins and AC. Bonanno (Gemstone, Canada, 2002) 229
  3. W. Fuquan, 'A gemological study of turquoise in china', Gems & Gemology 22(1) (1986) 35 https://doi.org/10.5741/GEMS.22.1.35
  4. E. Fritsch, S.P. McClure, M. Ostrooumov, Y Andres, T. Moses, J.I. Koivula and RC. Kammerling, 'The identification of zachery-treated turquoise', Gems & Gemology 35(1) (1999) 4 https://doi.org/10.5741/GEMS.35.1.4
  5. Q. Lijian, Y Weixuan and Y Mingxin, 'Turquoise from hubei province, china', Journal of Gemmology 26(1) (1998) 1 https://doi.org/10.15506/JoG.1998.26.1.1
  6. K. Schmetzer and H. Bank, 'An investigation of synthetic turquoise and the turquoise substitute of Gilson', Journal of Gemmology 17(6) (1981) 386 https://doi.org/10.15506/JoG.1981.17.6.386
  7. V.C. Kim, S.W. Kim and P.C. Kim, 'A study on the identification of quartz and jadeite by the FT-IR', Journal of Crystal Growth 13(1) (2003) 41
  8. R. Dud'a and L. Rejl, 'Minerals of the world', 2nd ed., J. Bauer and J.H. Bernard, (Arch cape, New York, 1990) 104
  9. E. Fritsch and C.M. Stockton, 'Infrared spectroscopy in gem identification', Gems & Gemology 23(1) (1987) 18 https://doi.org/10.5741/GEMS.23.1.18
  10. T. Lind, K. Schmetzer and H. Bank, 'The identification of turquoise by infrared spectroscopy and X-ray powder diffraction', Gems & Gemology 19(3) (1983) 164 https://doi.org/10.5741/GEMS.19.3.164
  11. E. Fritsch and G.R Rossman, 'An update on color in gems. Part 3: Colors caused by band gaps and physical phenomena', Gems & Gemology, 24(2) (1988) 81 https://doi.org/10.5741/GEMS.24.2.81