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Fluorescence image of Aurora Butterfly of Peace

An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemmology

Sally Eaton-Magaña and Christopher M. Breeding, April 28, 2016

Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.

Real-Time Microradiography of Pearls: A Comparison Between Detectors

Stefanos Karampelas, Abeer Tawfeeq Al-Alawi, and Ali Al-Attawi, January 26, 2018

Compares the image quality provided by real-time microradiographic imaging (RTX) units fitted with two different detectors: an image intensifier (II) and a flat panel detector (FPD).

Figure 1. One of GIA’s new LA-ICP-MS corundum calibration standards sets (set number 1); the epoxy disk containing the set is 1.5 inches in diameter. NIST SRM 610 and 612 glass standards are included to account for trace and non-trace elements, such as those found in inclusions, that were not incorporated into the synthetic sapphire crystals grown for standards. Photo by Jennifer Stone-Sundberg.

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

Jennifer Stone-Sundberg, Timothy Thomas, Ziyin Sun, Yunbin Guan, Zachary Cole, Randy Equall, and John L. Emmett, January 26, 2018

Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.

Emerald crystals from Colombia, Afghanistan, and Zambia

Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia

D. Brian Thompson, Christian J. Bayens, Matthew B. Morgan, Taylor J. Myrick, and Nealey E. Sims, November 8, 2017

Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.

Fluorescence produced by optical defects in diamond: measurement, characterisation and challenges

Yun Luo, July 24, 2013

How variations in UV lamp output can affect observed fluorescence colour and intensity.

Characterisation of “Green Amber” With Infrared and Nuclear Magnetic Resonance Spectroscopy

Ahmadjan Abduriyim, et al.

A peridot-like bright greenish yellow to green gem material called “green amber” has recently appeared in the gem market.

X-ray Computed Microtomography: Distinguishing Natural Pearls from Beaded and Non-Beaded Cultured Pearls

The distinction of natural from cultured pearls has traditionally been based on X-radiography.

Spectral Differentiation Between Copper and Iron Colourants in Gem Tourmalines

Paul B. Merkel and Christopher M. Breeding

The authors used Vis-NIR spectral measurements combined with LA-ICP-MS data to investigate the usefulness of absorption spectra.

A Mixture of Natural and Cultured Pearls

X-ray Computed Microtomography Applied to Pearls: Methodology, Advantages and Limitations

Stefanos Karampelas, Jürgen Michel, Mingling Zheng-Cui, Jens-Oliver Schwarz, Frieder Enzmann, Emmanuel Fritsch, Leon Leu, and Michael S. Krzemnicki

X-ray computed microtomography reveals the internal features of pearls in great detail.

Coloured Diamonds in the Aurora Butterfly of Peace Collection

The “Type” Classification System of Diamonds and Its Importance in Gemmology

Christopher M. Breeding and James E. Shigley, June 1, 2009

Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.

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Article Search Results

Types

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Gemstones

Gemstones

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