Visualization of the internal structures of cultured pearls by computerized X-ray microtomography

Wehrmeister, U.; Goetz, Hermann; Jacob, Dorrit E.; Soldati, Analía Leticia; Xu, Weiqing; Duschner, H.; Hofmeister, Wolfgang

doi:10.15506/jog.2008.31.1.15

Cited by 20 publications

(20 citation statements)

References 17 publications

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“…However, for decades by far the most important approach to identifying natural and cultured pearls has been X-radiography and, in more recent years, micro-CT (Anderson, 1932;Farn, 1986;Kennedy, 1998;Scarratt et al, 2000;Schlüter et al, 2005;Hänni, 2006;Strack, 2006;Wehrmeister et al, 2008;Sturman, 2009;Karampelas et al, 2010;Krzemnicki et al, 2010;Cartier and Krzemnicki, 2013;Rosc et al, 2016). Both methods enable the visualization and interpretation of internal features in pearls such as cavities, ring structures, dehydration fissures and bead structures.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous X-Radiography, Phase-Contrast and Darkfield Imaging to Separate Natural from Cultured Pearls

Krzemnicki¹,

Hanser²,

Revol³

2017

Journ of Gemm

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The separation of natural from cultured pearls is mainly based on the interpretation of their internal structures, which traditionally have been visualized by X-radiography and more recently by X-ray computed microtomography (micro-CT). In this study, the authors present a new analytical approach using a grating interferometer, which simultaneously generates an X-radiograph, a phase-contrast image and a small-scale scattering or darkfield image. The latter two additional images provided by this technique offer detailed and complementary information, as they are especially sensitive for visualizing tiny material inhomogeneities in pearls such as fissures, organic layers and cavity structures. Using seven selected natural and cultured pearl samples and a strand of non-beaded freshwater cultured pearls, the authors demonstrate that this new analytical approach offers versatile and rapid pearl identification possibilities, especially as it is possible to analyse not only single loose pearls but also entire strands and necklaces. Compared to micro-focus digital radiography and micro-CT, certain limitations in resolution still remain with the described prototype setups, and as such this new methodology should be considered a helpful complementary technique to the classical radiography of pearls.

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Section: Introductionmentioning

confidence: 99%

Simultaneous X-Radiography, Phase-Contrast and Darkfield Imaging to Separate Natural from Cultured Pearls

Krzemnicki¹,

Hanser²,

Revol³

2017

Journ of Gemm

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“…There are several reports on the Xray computed microtomography (μ-CT) analysis of natural pearls [16][17][18]. Earlier, Krzemnicki et al used μ-CT for the analysis of the natural pearl stones and in the same text they also mentioned the advantage and limitation of the technique in pearl analysis [19].…”

Section: Introductionmentioning

confidence: 99%

Surface and bulk 3D analysis of natural and processed ruby using electron probe micro analyzer and X-ray micro CT scan

Sahoo

Singh

Mishra

2016

Journal of Electron Spectroscopy and Related Phenomena

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“…differentiating between their natural or cultured formation; Figure 1) has been a crucial task for gemmologists, given the enormous differences in their rarity and price. Pearl identification is mostly based on the interpretation of internal structures, traditionally visualized by imaging methods such as X-ray radiography (Anderson, 1932;Scarratt et al, 2000;Strack, 2006;Sturman, 2009) and, more recently, X-ray computed microtomography (Wehrmeister et al, 2008;Karampelas et al, 2010;Krzemnicki et al, 2010;Otter et al, 2014) and X-ray phase contrast and darkfield imaging (Revol et al, 2016;Krzemnicki et al, 2017).…”

mentioning

confidence: 99%

Neutron Radiography and Tomography: A New Approach to Visualize the Internal Structures of Pearls

Hanser¹,

Krzemnicki²,

Grünzweig³

et al. 2018

Journ of Gemm

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Non-destructive imaging of the internal structures of pearls has so far been mainly based on X-ray imaging methods. As organic matter is almost transparent to X-rays, the identification of some structures can be difficult. This study shows that neutron imaging can be a helpful complementary method to visualize structures inside pearls beyond standard X-ray radiography and tomography, as neutrons are highly attenuated by hydrogen-bearing (organic) matter within pearls. The use of neutron radiography and tomography is shown for selected natural and cultured pearls (beaded and non-beaded). In addition, we present neutron phase contrast and darkfield images of a beaded cultured pearl, in analogy to X-ray phase contrast and darkfield imaging described in a previous study. While neutron imaging of pearls is particularly useful for understanding material inhomogeneities and void structures, this methodology is currently only available at large-scale facilities that are equipped to deal with nuclear reactions.

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Visualization of the internal structures of cultured pearls by computerized X-ray microtomography

Cited by 20 publications

References 17 publications

Simultaneous X-Radiography, Phase-Contrast and Darkfield Imaging to Separate Natural from Cultured Pearls

Simultaneous X-Radiography, Phase-Contrast and Darkfield Imaging to Separate Natural from Cultured Pearls

Surface and bulk 3D analysis of natural and processed ruby using electron probe micro analyzer and X-ray micro CT scan

Neutron Radiography and Tomography: A New Approach to Visualize the Internal Structures of Pearls

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