Identification of deposit types of natural corundum by PIXE

Chulapakorn, Thawatchart; Intarasiri, S.; Bootkul, D.; Singkarat, S.

doi:10.1016/j.nimb.2013.12.034

Cited by 9 publications

(10 citation statements)

References 10 publications

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“…3 As a gemstone, sapphire is one of the most valuable gemstones and is produced in many countries worldwide, for example, Myanmar, Thailand, Sri Lanka, Australia, etc. [4][5][6][7] The sapphire ores in the Shandong province are the largest reserves and have the best quality in China; it is located in the western part of the Tan-Lu fault zone, southeast of the North China Craton. 8 To the best of our knowledge, the gemological properties, mineralogical properties, chromogenic mechanism, color modication and inclusion study of Shandong sapphires have been investigated systematically and thoroughly.…”

Section: Introductionmentioning

confidence: 99%

Cause analysis of chatoyancy of sapphires from Shandong, China

2019

RSC Adv.

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Section: Introductionmentioning

confidence: 99%

Cause analysis of chatoyancy of sapphires from Shandong, China

2019

RSC Adv.

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“…According to Sutherland et al (2015) (Fig. 6a) and Chulapakorn et al (2014), the (V + Cr) vs. (Fe + Ti) plot, as well as the high Ti content (> 300 ppm) and low Fe amount (< 4200 ppm), show that all sapphires analysed have a metamorphic origin, thus indicating Sri Lankan or Myanmarese deposits (Lucas et al, 2014;Sutherland et al, 2015;Pehrson, 2017). The Fe vs. V diagram published by Atikarnsakul et al (2018) does not allow us to choose between these two sources (Fig.…”

Section: Sapphirementioning

confidence: 86%

A gemmological study of the reliquary crown of Namur, Belgium

Bruni¹,

Hatert²,

George

et al. 2021

Eur. J. Mineral.

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Abstract. The reliquary crown, hosted in the diocesan museum of Namur, was produced during the beginning of the 13th century to shelter a fragment of the holy crown of thorns. This beautiful piece of goldsmithery is made of eight gold plates, topped by round lobes, and connected to each other by hinges blocked with a pin decorated by a pearl. The crown is decorated by filigrees, flowers, and approximately 400 pearls and coloured (green, reddish pink, turquoise, red, blue) stones showing simple cutting with various sizes and shapes. Raman and portable X-ray fluorescence spectrometer (pXRF) techniques have been used to determine the nature and sources of all samples, as well as the composition of filigrees. Analyses have identified emeralds from Pakistan, reddish pink spinels from Tajikistan, red almandine garnets from India, turquoise from Iran, blue sapphires from Sri Lanka or Myanmar, and European pearls. The filigrees contain approximately 86 wt % Au, 7 wt % Ag, and 7 wt % Cu, thus confirming a gold-rich composition. The gemstones, contemporary with the crown, probably arrived in Europe by the silk trade road.

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“…The measurement demonstrated the accuracy of the experiment setup to be within ≈8%. [22] PIXE analysis revealed relatively high (>0.1 wt%) FeO content (0.5212-1.8028 wt%; avg. 0.8486 wt%) while TiO 2 content was generally low (<0.1 wt%) (0.0134-0.5194 wt%; avg.…”

Section: Proton-induced X-ray Emission (Pixe)mentioning

confidence: 99%

Investigation of Blue Coloration in Sapphires Using X‐Ray Absorption Near‐Edge Structure Spectroscopy (XANES)

Amphon

Chankhantha

Thammajak³

et al. 2022

Cryst. Res. Technol.

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The color of blue sapphire has long been explained using the intervalence charge‐transfer (IVCT) [Fe2+‐Ti4+ and/or Fe2+‐Fe3+] theory, in which the blue can be reduced by thermal (heat) treatment in oxidizing condition to alter Fe2+ (FeO) to Fe3+ (Fe2O3). However, the color mechanism is not well understood. Recently, the band gap theory proposes that iron (Fe) in sapphire always presents as Fe3+, and the blue is caused by Fe3+‐Ti4+ pair, hence thermal treatment does not alter Fe oxidation. The UV–Vis–NIR, Proton‐Induced X‐ray Emission (PIXE), and X‐ray Absorption Near‐Edge Structure (XANES) techniques are carried out before and after treatment to prove this issue. The absorption spectra are slightly lower after treatment, corresponding with the reduction of blue color in all samples. XANES data reveal mixture of Fe2+ and Fe3+ (mainly Fe3+) in all samples, and show insignificantly change after heated which rather supports the band gap theory. However, calculation based on linear combination fitting (LCF) technique shows a slight change in the oxidation from Fe2+ to Fe3+ which rather supports the IVCT theory. It is noted that the highest change is found in the lowest ratio of Fe:Ti sample, while the lowest change is conversely.

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Identification of deposit types of natural corundum by PIXE

Cited by 9 publications

References 10 publications

Cause analysis of chatoyancy of sapphires from Shandong, China

Cause analysis of chatoyancy of sapphires from Shandong, China

A gemmological study of the reliquary crown of Namur, Belgium

Investigation of Blue Coloration in Sapphires Using X‐Ray Absorption Near‐Edge Structure Spectroscopy (XANES)

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