Electron Backscatter Diffraction has been largely used in the metallurgic and material sciences and until now, has found few applications in the forensic sciences. One of the few utilizations of this ...technique in forensic science is in firearm serial number restoration as a complementary technique to the time-consuming and tedious chemical etching methods. This research aims to expand the uses of Electron Backscatter Diffraction in the forensic sciences as it applies to other types of samples, specifically as it pertains to forensic mineral analysis. Electron Backscatter Diffraction offers the analyst information regarding crystal structure of a material, so long as the sample is crystalline in nature. Minerals, many of which are crystalline in nature, can be analyzed using Electron Backscatter Diffraction. The Electron Backscatter Diffraction instrumentation used to achieve these patterns is coupled with a Scanning Electron Microscope and Energy Dispersive X-ray Spectrometer. These three instruments provide the analyst information of morphology, elemental composition, and of course, crystal structure. This combination of information in one single system is the most attractive feature of this method.Minerals have long been encountered in items of forensic importance, primarily as the main constituent of the inorganic portion of soil. Scientists have determined numerous methods to analyze this type of evidence by its mineral content, to determine if two samples came from a common origin. This information can aid in a forensic investigation to determine if a suspect has ever been at a crime scene, or with the use of geo-sourcing, determine where a crime scene is located.Polymorphisms are of special importance in forensic science as they further allow the differentiation of samples based on their crystal structure. By many of the currently used forensic techniques for analyzing the mineral fraction of soil samples, only the chemical composition is determined, by the physical properties of the bulk sample assessed. However, with the use of Electron Backscatter Diffraction, one can determine the crystal structure and determine the polymorph present. Determining the crystal structure of a mineral can help to add to the information about a sample, either as exclusionary or inclusionary evidence in a forensic investigation. This study aims to examine minerals commonly found in nature, which could ultimately become forensic evidence, and the ability of Electron Backscatter Diffraction to obtain crystal information from a single grain or crystal. The parameters necessary to achieve this information will be thoroughly studied. Various sample preparation techniques will be considered. The applicability of this technique to gem authentication will be tested. Lastly, this research aims to answer the question as to whether Electron Backscatter Diffraction can be successfully used to analyze minerals in real forensic case samples.
Display omitted
•Process, medical and environmental mineralogy collectively contribute to sustainability.•Pre-2000 case studies mostly focused on process mineralogy alone.•Post-2000 case studies more ...consciously interface the domains of applied mineralogy.•Reviewed case studies highlight important developments in mineralogy tools.
It is well known that mining is an essential enabler of sustainable development. Understanding and appreciating the mineralogy of the ores and waste material we produce is a key component of this. This paper considers the contribution of mineralogy to sustainability through the mine life cycle, looking through the lenses of process mineralogy, environmental mineralogy and medical mineralogy and their relationship to the pillars of sustainability - profit, planet, and people, respectively. Using several case studies, examples will be shown as to how the application of mineralogy and the tools used for characterisation have evolved over the decades from the early pioneering mineralogists to some of the most recent work where mineralogy is fully integrated into all aspects of ore and waste use, and valorisation.
Studies of native gold sampled from drainages are an important exploration tool and an increasing number of studies have evaluated the characteristics of detrital gold to understand gold camps and ...the deposits within them. This thesis focuses on the compositional analysis of the native gold sampled from drainages. By sampling the detrital gold eroded out from a gold deposit, the gold particles can be compared to in situ gold particles, thereby allowing correlation with knowledge gained from traditional mineralogy and an assessment of the gold on a deposit (macro) scale. This provides a novel assessment of how variable a deposits' mineralisation might be which can provide useful context to micro scale observations. To develop, investigate and test correlative uses of detrital gold samples with traditional mineralogy, three different studies were conducted at the Cononish Mine (Scotland), Curraghinalt Mine (Northern Ireland) and the Atlin Gold Camp (British Columbia). This work demonstrates that populations of gold particles sampled directly from mines differ from detrital populations obtained from drainages. Detrital populations are considered more representative of the mineralisation within a deposit, as they are the residual lags resultant from the erosion of a huge volume of material. Correlation between gold particles in ore and in detrital population provides a context to the compositions in ore on a deposit/ system scale. By identifying the importance of specific gold compositions within the deposit observations of the ore assemblages associated with gold events can be examined in a deposit scale context which would otherwise not be possible. This allows temporal and spatial differences between ore samples to be evaluated for significance. This provides a contextual framework for observed changes in the ore assemblages, and therefore mineralising fluids. This work presents a method for relating micro to macro scale characterisations of a gold mineralisation using gold compositions. It demonstrates that detrital gold studies can improve the understanding of gold mineralisation and, critically, can provide a context for the gold mineralisation across multiple scales within a deposit, which through traditional mineralogy alone is difficult to achieve.
