Network Analysis of Virginia’s Mineralogical Systems

The principal objective of this study was to use network analysis to identify spatial, geomorphic, physical, and chemical patterns in Virginia’s mineralogical systems. Mineralogical and locality data from mindat.org were visualized as a bipartite force- directed network of the minerals and the counties of Virginia in which they occur. Mineral nodes were sized to represent the number of counties the minerals are found in (i.e., frequency of occurrence) and county nodes were sized to represent the number of minerals found in that county (i.e., mineral diversity). Furthermore, the nodes were colored to display selected attributes of the mineral-county data. County nodes were colored by their geomorphic regions of Virginia (i.e., Blue Ridge, Piedmont, Coastal Plain, Appalachian Plateau, and Valley and Ridge), whereas mineral nodes were represented with many attributes, including Mohs hardness, carbon content, crystal structure, and mineral classification. This method of data visualization revealed several patterns, including the abundance of softer and carbon-bearing minerals near the Valley and Ridge counties, the abundance of silicate minerals near the Piedmont and Coastal Plain counties, and the related distribution of gold, silver, and copper.