Darryl Hoppe is a Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Professional Experience
2018 - Present: Geologist, U.S. Geological Survey, GEMSC, Reston, Virginia
2016 - 2018: Science Tech, Lynxnet LLC, Contractor to the U.S. Geological Survey
Science and Products
Electron microprobe analyses of sphalerite from Central and East Tennessee mining districts, the Red Dog mining district (AK), and the Metaline mining district (WA)
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 in the 'Related External Resources' section below.
Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
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
Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the mechanisms of Ge e
Pre-mining environmental baseline characterization of the Hajigak iron deposit: 2019 field season
These data include geochemical analyses of rock, mine waste, sediment, soil, and water samples collected from the Hajigak iron deposit, Bamyan and Wardak Provinces, Afghanistan in 2019.
Pre-mining environmental baseline characterization of the Aynak copper deposit: 2019 field season
These data include geochemical analyses of rock, mine waste, sediment, and soil samples collected from the Aynak copper deposit, Logar Province, Afghanistan in 2019. In addition, these data include geochemical analyses of water samples collected from the Aynak copper deposit, Logar Province, Afghanistan in 2019.
Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.
Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared using XANE
Elemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publi
Electron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
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 zi
Geochemistry and mineralogy of metallurgical slag
Slag is a waste product from the pyrometallurgical processing of natural ores or the recycling of man-made materials. This chapter provides an overview of the geochemical and mineralogical characteristics of different types of slag. A review of the analytical methods used to determine these characteristics is also provided. Ferrous slags include blast furnace, steelmaking, and ferroalloy slags; th
Geochemical characterization of iron and steel slag and its potential to remove phosphate and neutralize acid
Iron and steel slags from legacy and modern operations in the Chicago-Gary area of Illinois and Indiana, USA, are predominantly composed of Ca (10 - 44 wt. % CaO), Fe, (0.3 - 28 wt. % FeO), and Si (10 - 44 wt. % SiO2), with generally lesser amounts of Al (< 1 15 wt. % Al2O3), Mg (2 11 wt. % MgO), and Mn (0.3 9 wt. % MnO). Mineralogy is dominated by CaMgAl silicates, FeCa oxides, Ca-carbonates,
Science and Products
- Data
Electron microprobe analyses of sphalerite from Central and East Tennessee mining districts, the Red Dog mining district (AK), and the Metaline mining district (WA)
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 in the 'Related External Resources' section below.Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
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 tooTrace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the mechanisms of Ge ePre-mining environmental baseline characterization of the Hajigak iron deposit: 2019 field season
These data include geochemical analyses of rock, mine waste, sediment, soil, and water samples collected from the Hajigak iron deposit, Bamyan and Wardak Provinces, Afghanistan in 2019.Pre-mining environmental baseline characterization of the Aynak copper deposit: 2019 field season
These data include geochemical analyses of rock, mine waste, sediment, and soil samples collected from the Aynak copper deposit, Logar Province, Afghanistan in 2019. In addition, these data include geochemical analyses of water samples collected from the Aynak copper deposit, Logar Province, Afghanistan in 2019.Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared using XANEElemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publiElectron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
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 zi - Publications
Geochemistry and mineralogy of metallurgical slag
Slag is a waste product from the pyrometallurgical processing of natural ores or the recycling of man-made materials. This chapter provides an overview of the geochemical and mineralogical characteristics of different types of slag. A review of the analytical methods used to determine these characteristics is also provided. Ferrous slags include blast furnace, steelmaking, and ferroalloy slags; thGeochemical characterization of iron and steel slag and its potential to remove phosphate and neutralize acid
Iron and steel slags from legacy and modern operations in the Chicago-Gary area of Illinois and Indiana, USA, are predominantly composed of Ca (10 - 44 wt. % CaO), Fe, (0.3 - 28 wt. % FeO), and Si (10 - 44 wt. % SiO2), with generally lesser amounts of Al (< 1 15 wt. % Al2O3), Mg (2 11 wt. % MgO), and Mn (0.3 9 wt. % MnO). Mineralogy is dominated by CaMgAl silicates, FeCa oxides, Ca-carbonates,