Online

Accorsi, Gina

Geology

2017

MS

In accordance with the 2010 Dodd-Frank Act, conflict minerals refer to gold, tantalum, tin, and tungsten bearing minerals sourced from the Democratic Republic of Congo (DRC) that have been mined illegally and used to funnel funds to rebel forces. In response to an increasing demand for these metals used in cellphones, computers, and other popular technologies, Dodd-Frank mandates that industrial consumers demonstrate due diligence and assure that the materials they use have been extracted legally. Because current chain-of-custody methods have not been effective in sourcing ores, a study was undertaken whereby the range of mineralogical characteristics of 15 samples along the wolframite solid solution series were determined in order to ascertain if differences in these characteristics would permit fingerprinting of the source deposit of wolframite, of which the DRC is the world’s fifth largest producer. For these 15 samples, single-crystal X-ray structure and powder X-ray diffraction studies have been conducted; major, minor and trace element chemistry has been determined using ICP-MS and ICP-OES; and Raman spectroscopy has been carried out. Finally, statistical methods were used to determine relationships between samples, and the results of that mathematical work show that there is no firm method at the present time of determining the provenance of a sample based on the information of the crystal structure, diffraction patterns, vibrational frequencies/scattering, or major and trace elemental chemistry. This study elucidates the range of mineralogical properties along the hübnerite-ferberite solid solution series while working towards to development of an analytical technique that is affordable, practical, accessible and effective for industrial consumers seeking product certification and compliance with the 2010 Dodd-Frank Act.