Gem-Quality Diamonds: Source Discrimination

Coney, L.; Moila, A.; Quadling, Amanda

doi:10.2113/gssajg.115.1.33

Cited by 11 publications

(21 citation statements)

References 24 publications

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“…Published applications include successful attempts to fingerprint so-called 'conflict diamonds' [150,151], columbite-tantalite and other sought-after ores (e.g., [152,153]). Potential can also be recognised in areas such as uranium concentrates.…”

Section: Element Deportment Geometallurgy and Forensic Applicationsmentioning

confidence: 99%

Trace Element Analysis of Minerals in Magmatic-Hydrothermal Ores by Laser Ablation Inductively-Coupled Plasma Mass Spectrometry: Approaches and Opportunities

et al. 2016

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Laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) has rapidly established itself as the method of choice for generation of multi-element datasets for specific minerals, with broad applications in Earth science. Variation in absolute concentrations of different trace elements within common, widely distributed phases, such as pyrite, iron-oxides (magnetite and hematite), and key accessory minerals, such as apatite and titanite, can be particularly valuable for understanding processes of ore formation, and when trace element distributions vary systematically within a mineral system, for a vector approach in mineral exploration. LA-ICP-MS trace element data can assist in element deportment and geometallurgical studies, providing proof of which minerals host key elements of economic relevance, or elements that are deleterious to various metallurgical processes. This contribution reviews recent advances in LA-ICP-MS methodology, reference standards, the application of the method to new mineral matrices, outstanding analytical uncertainties that impact on the quality and usefulness of trace element data, and future applications of the technique. We illustrate how data interpretation is highly dependent on an adequate understanding of prevailing mineral textures, geological history, and in some cases, crystal structure.

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Section: Element Deportment Geometallurgy and Forensic Applicationsmentioning

confidence: 99%

Trace Element Analysis of Minerals in Magmatic-Hydrothermal Ores by Laser Ablation Inductively-Coupled Plasma Mass Spectrometry: Approaches and Opportunities

et al. 2016

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“… Coney et al. (2012) , describe diamond discrimination studies from a physical and chemical perspective from as early as 1975, when Harris et al.…”

Section: Previous Studiesmentioning

confidence: 99%

“…(2005) were responsible for the development of standards for LA-ICP-MS analysis to ensure that matrix-matched analytical protocols were implemented, while McNeill et al. (2009) adapted the methodology to ensure the lowest detection limits possible ( Coney et al., 2012 ). Dalpé et al.…”

Section: Previous Studiesmentioning

confidence: 99%

Diamond fingerprinting for source discrimination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and Fourier transform infrared spectrometry (FTIR)

Brill

Lilimu

Chetty

2020

Heliyon

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The Kimberley Process Certification Scheme (KPCS) was established in 2000 as a means of controlling the flow of conflict diamonds, mostly, from the African continent. In 2013, the KPCS imposed an embargo on diamonds from the Central African Republic (CAR). Since then the embargo has been lifted in certain prefectures of the country, however, smuggling is suspected from non-compliant areas. Three parcels of diamonds suspected to have mining origins in the CAR, were analysed. These diamonds were investigated for their morphological and chemical characteristics, to establish a diamond fingerprint and to determine if these diamonds had the same fingerprint as previously analysed diamonds from CAR or the Democratic Republic of the Congo (DRC). The analyses of these diamonds were included in the already established diamond database of rough diamonds from the African continent. The morphological characteristics identified included the mass (ct), colour, surface coatings, dominant, secondary and tertiary form, shape, breakage, inclusions, abrasion and surface features that are specific to octahedral, dodecahedral and cubic shapes. The morphological characteristics determined from the diamonds revealed that morphology alone cannot be used as a discriminatory method for diamond fingerprinting. Fourier transform infrared spectroscopy (FTIR) identified the nitrogen concentration and aggregation state of that N. This allowed for the typing of the diamonds as Type I (containing N) and Type II (containing no measureable N). The concentration of N in the three parcels is less than 600 ppm. Further classification of Type I diamonds was performed according to the N aggregation state as single, double or four-fold. The vast majority of diamonds show a combination of nitrogen aggregation states while few were classified as Type II. Fourier transform IR showed no discernible trends between the current study and the established database. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used as a means of determining the trace element concentrations of 69 Ga, 88 Sr, 89 Y, 90 Zr, 93 Nb, 133 Cs, 137 Ba, 139 La, 140 Ce, 141 Pr, 146 Nd, 147 Sm, 153 Eu, 157 Gd, 159 Tb, 163 Dy, 165 Ho, 166 Er, 169 Tm, 172 Yb, 175 Lu, 178 Hf, 181 Ta, 232 Th and 238 U. Laser ablation ICP-MS determined that not all elements produce statistically viable data, however, the data could still be used to discern trace element d...

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“…In addition to metal products, there has also been an attempt to develop a fingerprinting method for characterising diamonds, which are illicitly mined in a number of countries in Africa, but the research carried out in South Africa has shown that this is very difficult to do (Coney et al, 2012).…”

Section: Africamentioning

confidence: 99%