The Spectral Characteristics Of Some Common Iron Gem

Gemstones can be used as decorative stones are used in mineral and material. Nature of mineral raw materials can be used as precious gemstones are about 130 species, accounting for 90% of gem materials, such as diamond, sapphire, chrysoberyl and peridot. Iron-induced color from the mineral species occupy a relatively large proportion.The abundance of iron on Earth is about 5%, after the formation of geological gem material will exist in both a certain degree of iron ions, such as the blue sapphire, peridot, aquamarine, almandine, spinel and so on. Because of its containing divalent iron, trivalent iron or a combination of reasons exist, gems show different degrees of blue, yellow, and green, purple, yellow, and thus to study the coloring mechanism of iron-containing precious stones caused difficulties.In this paper, mineral physics point of view of calculating the energy levels of iron orbit splitting and electronic transition energy, and get a theoretical UV-visible absorption spectra, and then by computer simulation of several common gemstones crystal structure of iron and iron absorption line and test results obtained with the actual comparison, analysis, to be able to demonstrate stones contain the signature spectra of iron to analysis their coloration mechanism.Through the establishment of sapphire and spinel crystal structure of two kinds of simulation models and explore alternatives to replace the role of iron, lead crystal field energy of what changes occur and to further explore the gem of the coloration mechanism.From the perspective of mineral physics, and calculate the energy levels of iron ions and the transition energy splitting of the absorption lines assigned to conduct a reasonable and with the sample of UV-visible absorption spectra and visible absorption spectra compared to the time to observe whether the three match. Application of mineral physics-related theory and references are cited data on iron-containing gems of electronic interaction between iron parameters B, C was calculated results for B=614;C=3212. The results show that the use of Dq, B, C parameters of electronic transitions of iron ions the theoretical calculations agree well with the experimental values, thereby realizing the right gems in the ferrous iron absorption band electronic transitions a reasonable assignment. As the iron gem also contains many other types of transition metal ions, so the optical absorption patterns are usually very complicated, for the absorption band of the fit and has not yet assigned to a full and reasonable explanation.In this paper, precious stones in the common start of iron ions with crystal field theory and its method of optical absorption spectra in the hope of other transition metal ions for the study of the absorption spectra provide a way.