Effect of Beryllium Heat Treatment in Synthetic Ruby

Monarumit, Natthapong; Lhuaamporn, Thanapong; Satitkune, Somruedee; Wongkokua, Wiwat

doi:10.1007/s10812-019-00845-x

Cited by 9 publications

(7 citation statements)

References 13 publications

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“…Figure 2 presents the monochromatic UV-Vis-NIR spectra of the natural and Be-treated ruby and yellow sapphire samples. The absorption spectra of the natural and Be-treated ruby samples exhibit similar patterns, consistent with synthetic samples from previous research [6]. Both spectra show the characteristic absorption peaks of Cr 3+ at 405 nm, 555 nm, and 693 nm.…”

Section: Resultssupporting

confidence: 87%

“…However, this technique does not explain of how Be influences the color mechanism. Some research has suggested that the Be 2+ donor state is responsible for producing an orange color in Be-treated synthetic ruby [6], as well as the yellow color in Be-treated yellow sapphire through Fe 3+ -Be 2+ mixed donor states [7], using the polychromatic UV-Vis-NIR spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

“…In most gem laboratories, a monochromatic UV-Vis-NIR absorption spectrophotometer is used to measure the peak position of trace elements related to the coloration of [8][9]. However, there is no evidence that this technique can be used to detect the Be signal until the detection of the Be 2+ donor state and Fe 3+ -Be 2+ mixed donor states using a polychromatic UV-Vis-NIR spectrophotometer has been reported [6][7]. In some cases, there is no need to differentiate between monochromatic and polychromatic UV-Vis-NIR spectrophotometers as the spectra obtained may be identical [10].…”

Section: Introductionmentioning

confidence: 99%

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An application of polychromatic UV-Vis-NIR spectroscopy on detection of beryllium treatment in ruby and yellow sapphire

Monarumit,

Lhuaamporn,

Schwarz

et al. 2023

J. Phys.: Conf. Ser.

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The ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy has been essentially used to characterize gem materials and their treatments. The spectrophotometer was designed using a diffraction grating to provide the monochromatic light from a tungsten lamp in analyzing a sample. The signal is recorded by a photodiode, resulting in a characteristic spectrum of a gemstone sample. While the monochromatic UV-Vis-NIR spectrophotometer is used for characterizing treated ruby and yellow sapphire samples; however, some indicative characteristic absorptions could be missing. The technique may not be able to clearly differentiate the Be-treated ruby and yellow sapphire samples from the natural ones. Therefore, polychromatic UV-Vis-NIR spectroscopy could be utilized. The polychromatic light from a tungsten lamp passing through the sample provides the polychromatic UV-Vis-NIR spectrum produced by the spectrophotometer comprising a diffraction grating with a diode array CCD or CMOS detector. Both natural and Be-treated ruby and yellow sapphire samples were measured using both spectrophotometers. The experiment reveals that the polychromatic UV-Vis-NIR excitation spectroscopy can be used to differentiate the Be-treated ruby and yellow sapphires from the natural ones. Moreover, the polychromatic UV-Vis-NIR spectrophotometer offers the advantages of portability, measuring time, and low cost.

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Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An application of polychromatic UV-Vis-NIR spectroscopy on detection of beryllium treatment in ruby and yellow sapphire

Monarumit,

Lhuaamporn,

Schwarz

et al. 2023

J. Phys.: Conf. Ser.

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“…In this work, the thermal treatments on the rubies have been conducted in an open environment (oxidizing) and other types of gaseous environments have not been considered. For instance, Beryllium heat treatment causes rubies to take on a more vivid red color [38]. The mixed gas environment of hydrogen and oxygen causes the samples to turn from red to orange [39].…”

Section: Discussionmentioning

confidence: 99%

Chemical Composition and Spectroscopic Characteristics of Heat-Treated Rubies from Madagascar, Mozambique and Tanzania

Yang

et al. 2023

Crystals

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The chemical composition and spectra of rubies heat-treated with high temperatures (above 1200 °C) from Madagascar, Mozambique and Tanzania were analyzed by electron microprobe, LA-ICP-MS, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-VIS spectroscopy. Compared with untreated rubies, the red hue of treated ruby intensifies while its blue tint diminishes, leading to increased cracks. The infrared spectra exhibit a distinct absorption peak at 3738 cm−1, attributed to water because of thermal treatment. After heat treatment, the absorption intensity decreases. Ultraviolet radiation reveals an enhancement in the electron transition of Cr3+ and ion transition of Fe3+ and Fe2+, with a shift towards shorter wavelengths observed in the absorption bandwidth. These can be utilized to indicate the basis of ruby identification through heat treatment.

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“…The geological conditions for ruby formation are diverse [12]. Three major deposit types of gem-quality ruby exist: marble-hosted (Myanmar, Afghanistan, Vietnam); basalt-hosted (Thailand, Cambodia); and metasomatic type (Kenya, Sri Lanka, India) [13,14]. The gemological properties and geological settings of rubies from Madagascar and Mozambique are similar, and their distinction is therefore difficult [12].…”

Section: Introductionmentioning

confidence: 99%

Chemical and Spectral Variations between Untreated and Heat-Treated Rubies from Mozambique and Madagascar

Sun

Qin³

2022

Minerals

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The chemical composition and spectra of untreated and heat-treated rubies from Mozambique and Madagascar were analyzed by an electron probe microscopy analysis, laser ablation inductively coupled plasma quadrupole mass spectrometry, Fourier transform infrared spectroscopy, Raman spectroscopy and UV-visible spectroscopy. Due to the different content of Fe and different inclusions, rubies from Madagascar belong to alkaline basalt deposit, while rubies from Mozambique belong to amphibole metamorphic rock. The ruby samples were heated to 900 °C to change their color. As Fe and Ti ions can be transferred into different valences and diffused into the interior of rubies, Cr ions in cracks or cleavages entered the crystal lattice during heat treatment and the content of Fe and Ti decreased, while the content of Cr increased in heat-treated rubies. After heating, blue-purple decreased and the red hue increased, while the blue color band disappeared and yellow appeared in the cracks of the samples because of the chemical changes. Compared with untreated rubies, the infrared absorption peaks of 2123 cm−1 and 1990 cm−1 related to inclusions disappeared, and the existence of 3236 cm−1 and 3186 cm−1 absorption peaks was a typical characteristic of heat-treated ruby, which was produced by changes in its inclusion. In addition, due to the weakened charge transfer of Fe2+ and Ti4+ and the increasing reaction of Fe2+ → Fe3+ along with the heat treatment, the UV-visible absorption peak at 400 nm shifted to purple.

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Effect of Beryllium Heat Treatment in Synthetic Ruby

Cited by 9 publications

References 13 publications

An application of polychromatic UV-Vis-NIR spectroscopy on detection of beryllium treatment in ruby and yellow sapphire

An application of polychromatic UV-Vis-NIR spectroscopy on detection of beryllium treatment in ruby and yellow sapphire

Chemical Composition and Spectroscopic Characteristics of Heat-Treated Rubies from Madagascar, Mozambique and Tanzania

Chemical and Spectral Variations between Untreated and Heat-Treated Rubies from Mozambique and Madagascar

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