Electron microprobe analyses of sphalerite (ZnS) were collected on samples from current or past mining operations in the USA with a specific focus on germanium (Ge), a byproduct critical mineral recovered from sphalerite. Data and methods reported are part of a research study published here: Hayes SM, McAleer RJ, Piatak NM, White SJO, Seal RR II (2023), A novel nondestructive workflow for examining germanium and co-substituents in ZnS. Front. Earth Sci. 11:939700. doi: 10.3389/feart.2023.939700

Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-silicate, hemimorphite. Data and methods reported are part of a research study published here: White, S.J.O., Piatak, N.M., McAleer, R.J., Hayes. S.M., Seal, R.R. II, Schaider, L.A., Shine, J.P. Germanium redistribution during weathering of Zn mine wastes: implications for environmental mobility and recovery of a critical mineral"

Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations that were too low to generate a X-ray absorption spectra with an edge step. When applicable, Ge content in quartz was determined using XAS edge steps. Data and methods reported are part of a research study published here: Hayes SM, McAleer RJ, Piatak NM, White SJO, Seal RR II (2023), A novel nondestructive workflow for examining germanium and co-substituents in ZnS. Front. Earth Sci. 11:939700. doi: 10.3389/feart.2023.939700

Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations that were too low to generate a X-ray absorption spectra with an edge step. When applicable, Ge content in quartz was determined using XAS edge steps. Data and methods reported are part of a research study published here: Hayes SM, McAleer RJ, Piatak NM, White SJO, Seal RR II (2023), A novel nondestructive workflow for examining germanium and co-substituents in ZnS. Front. Earth Sci. 11:939700. doi: 10.3389/feart.2023.939700

This data release provides electron microprobe geochemical data that was collected as part of a scoping study to evaluate whether unconventional critical element resources may be associated with sediment-hosted copper systems in the Midcontinent Rift. We report abundances of trace elements in native copper and sulfide minerals in 12 thin sections from samples of the Mesoproterozoic lower Nonesuch Formation that were collected from underground exposures in the White Pine deposit. Approximately 350 spots were analyzed for Cu, Pb, Zn, Fe, Ni, Co, As, Sb, Ag, Hg, and S. The electron microprobe data were collected by personnel of the Central Region Minerals Program in Denver, Colorado, for the U.S. Geological Survey (USGS) Mineral Resources Program (MRP). An ASCII text file of results is provided in comma-separated by value (csv) format. The file has the name “White_Pine_EPMA_data.csv”.

This data release provides electron microprobe analyses of ore minerals from the Copperwood sediment-hosted stratiform copper deposit in the Upper Peninsula of Michigan. The minerals include bornite, chalcocite, native copper, native silver, and pyrite. Minerals were analyzed for Ag, As, Co, Cu, Fe, Hg, Ni, Pb, S, Sb, and Zn. Results with acceptable totals that lie between 98.5 and 101.5% show that these minerals are stoichiometric, with very limited substitution of other elements. The Copperwood copper deposit is a sediment-hosted stratiform copper deposit in the Presque Isle Syncline of the Upper Peninsula of Michigan. The Lower Copper Bearing Sequence has a 2018 mineral resource estimate of 42.2 million metric tons (Mt) of measured plus indicated mineral resources at an average grade of 1.60% Cu and 3.84 g/t Ag. The measured plus indicated mineral resource in the Upper Copper Bearing Sequence is estimated to be 7.1 Mt at an average grade of 1.21% Cu and 3.26 g/t Ag (Gignac, 2018). The mineral reserves for the Copperwood Project are estimated at 25.4 Mt at an average grade of 1.43% Cu and 3.83 g/t Ag (Gignac, 2018).

This data release provides electron microprobe analyses of ore minerals from the Copperwood sediment-hosted stratiform copper deposit in the Upper Peninsula of Michigan. The minerals include bornite, chalcocite, native copper, native silver, and pyrite. Minerals were analyzed for Ag, As, Co, Cu, Fe, Hg, Ni, Pb, S, Sb, and Zn. Results with acceptable totals that lie between 98.5 and 101.5% show that these minerals are stoichiometric, with very limited substitution of other elements. The Copperwood copper deposit is a sediment-hosted stratiform copper deposit in the Presque Isle Syncline of the Upper Peninsula of Michigan. The Lower Copper Bearing Sequence has a 2018 mineral resource estimate of 42.2 million metric tons (Mt) of measured plus indicated mineral resources at an average grade of 1.60% Cu and 3.84 g/t Ag. The measured plus indicated mineral resource in the Upper Copper Bearing Sequence is estimated to be 7.1 Mt at an average grade of 1.21% Cu and 3.26 g/t Ag (Gignac, 2018). The mineral reserves for the Copperwood Project are estimated at 25.4 Mt at an average grade of 1.43% Cu and 3.83 g/t Ag (Gignac, 2018).

This data set contains 99 electron microprobe analyses of cassiterite, chalcopyrite, galena, pyrite, sphalerite, and tetrahedrite from seven Sheep Creek drill core samples and one outcrop; and a table that describes the textures, mineralogy, and rock type of 15 thin sections of Sheep Creek drill core and observations from our study and from drill core logging by industry. These data were used to compare this prospect with others in the Bonnifield district. The data set also contains tables of sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon dates, zircon characteristics (crystal shape, external morphology, internal features, color, aspect ratio, and cathodoluminescence zoning), and 139 U-Th-Pb analyses of the zircons from 11 metaigneous rocks collected during 1997-2005 fieldwork in the Bonnifield mining district, Alaska Range. Our zircon geochronology indicates that volcanogenic massive sulfide deposits in the Bonnifield district are hosted in felsic metavolcanic rocks that yield ages based on weighted averages of 206 Pb/238U ages (± 2-sigma errors) of 362 ± 2 Ma. These rocks overlie the stratigraphic sequence at the Sheep Creek prospect, where metaigneous rocks give ages of 372 ± 4 Ma to 366 ± 4 Ma.

This dataset contains results from electron microprobe analyses for expanded and unexpanded vermiculite samples. These data are provide for samples of vermiculite ore, expanded vermiculite insulation, horticultural products, aggregate, and packing materials derived from mines near Enoree, South Carolina; Libby, Montana; Louisa, Virginia; Palabora, South Africa; Jiangsu, China; and Llano, Texas. An ASCII text file of results is provided in comma-separated by value (csv) format. The file has the name “vermiculite_probe_microanalyses_data.csv”.