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Mercury and the Making of California, Andrew Johnston's multidisciplinary examination of the history and cultural landscapes of California's mercury-mining industry, raises mercury to its rightful place alongside gold and silver in the development of the American West. Gold and silver could not be refined without mercury; therefore, its production and use were vital to securing power and wealth in the West. The first industrialized mining in California, mercury mining had its own particular organization, structure, and built environments. These were formed within the Spanish Empire, subsequently transformed by British imperial ambitions, and eventually manipulated by American bankers and investors. In California mercury mining also depended on a workforce differentiated by race and ethnicity. The landscapes of work and camp and the relations among the many groups involved in the industry-Mexicans, Chileans, Spanish, English, Irish, Cornish, American, and Chinese-form a crucial chapter in the complex history of race and ethnicity in the American West. This pioneering study explicates the mutual structuring of the built environments of the mercury-mining industry and the emergence of California's ethnic communities. Combining rich documentary sources with a close examination of the existing physical landscape, Johnston explores both the detail of everyday work and life in the mines and the larger economic and social structures in which mercury mining was enmeshed, revealing the significance of mercury mining for Western history.

Au-Hg-Ag phases have been described from a variety of metallogenic orebodies and the placer deposits derived from them. In many documented placer deposits, the phases typically occur intergrown as 'secondary' rims to primary Au-Ag grains. The origin of these rims has been ascribed to supergene redistribution reactions during deposition or to the effects of amalgamation (i.e. use of mercury) during mining for gold. Difficulties in determining compositions and crystal structures on such a small scale have made full characterisation of these phases problematic. This paper describes a new occurrence of these phases, found by accident during investigation of a historical concentrate of 'osmiridium' containing a number of gold grains from beach sands at Waratah Bay, in southern Victoria, Australia. The phases occur as rims to gold grains and are intergrown on a scale of tens of micrometres or less. Application of electron microprobe analysis (EPMA) and limited electron back-scattered diffraction (EBSD) was required to characterise them. These techniques revealed the presence of the approved mineral weishanite (Au-Hg-Ag) and a phase with compositional range Au2Hg-Au3Hg surrounding primary Au-Ag (electrum) containing trace amounts of Hg. EBSD analysis showed weishanite is hexagonal P63/mmc and Au2Hg to be hexagonal P63/mcm. Comparison with published data from other localities (Philippines, British Columbia and New Zealand) suggests weishanite has a wide compositional field. Textures shown by these phases are difficult to interpret, as they might form by either supergene processes or by reaction with anthropogenic mercury used during mining. However, in the absence of any historical evidence for the use of mercury for gold mining at Waratah Bay, we consider the formation of the Au-Hg phases is most probably due to supergene alteration of primary Au-Ag alloy containing small amounts of Hg. In addition to revealing some of the reaction sequences in the development of these secondary Au-Hg-Ag rims, this paper illustrates methods by which these phases can be more fully characterised and thereby better correlated with the Au-Hg synthetic system.

Cinnabar (α-HgS) is the most common sulfide of mercury while metacinnabar (β-HgS), a high-temperature homogeneous polymorph of the mercury sulfide, is relatively rare, and the α phase of cinnabar transforms to the β phase at 344 °C. Meanwhile, there is a complete isomorphic series between HgS and HgSe, and the occurrence of Se-bearing metacinnabar is of great significance for the exploration of selenium resources. We studied through microscopic observation, electron-probe microanalysis, X-ray diffraction and field emission scanning electronic microscopy (FESEM) the Se-bearing metacinnabar of the Wanshan mercury ore field of southeastern Yangtze Block. These analyses, combined with physicochemical phase diagrams, constrained the textural and chemical evolution during the formation process of Se-bearing metacinnabar. Se-bearing metacinnabar was found in altered carbonatite, intergrown with cinnabar, sphalerite, pyrite, realgar and quartz. The Se-bearing metacinnabar contains 77.66–84.01 wt.% Hg, 0.18–1.17 wt.% Zn with extensive isomorphic substitution of Se and S (2.79–14.77 wt.% Se, 6.15–11.82 wt.% S). The presence of impurity elements (e.g., Zn and Se) is considered to be the key factor in expanding the stable range of Se-bearing metacinnabar. The cinnabar generated by the transformation of Se-bearing metacinnabar is characterized by inclusions of Hg-bearing sphalerite and pores, which indicate that this process was carried out through a coupled dissolution–reprecipitation (CDR) reaction. The formation temperature of Se-bearing metacinnabar is higher than that of cinnabar, and according to the phase relations between sulfides and selenides, we propose that logfS2(g) of ore-forming fluids is constrained within −15.663 to −13.141, and logfSe2 < logfS2–3.994 (150 °C).

\"Mercury and the Making of California, Andrew Johnston's multidisciplinary examination of the history and cultural landscapes of California's mercury-mining industry, raises mercury to its rightful place alongside gold and silver in the development of the American West. Gold and silver could not be refined without mercury; therefore, its production and use were vital to securing power and wealth in the West. The first industrialized mining in California, mercury mining had its own particular organization, structure, and built environments. These were formed within the Spanish Empire, subsequently transformed by British imperial ambitions, and eventually manipulated by American bankers and investors. In California mercury mining also depended on a workforce differentiated by race and ethnicity. The landscapes of work and camp and the relations among the many groups involved in the industry--Mexicans, Chileans, Spanish, English, Irish, Cornish, American, and Chinese--form a crucial chapter in the complex history of race and ethnicity in the American West. This pioneering study explicates the mutual structuring of the built environments of the mercury-mining industry and the emergence of California's ethnic communities. Combining rich documentary sources with a close examination of the existing physical landscape, Johnston explores both the detail of everyday work and life in the mines and the larger economic and social structures in which mercury mining was enmeshed, revealing the significance of mercury mining for Western history\"--Unedited summary from book jacket.

Granite-related W-Sn ore systems are commonly associated with coeval Pb-Zn mineralization. It remains unclear whether these metals are derived from the same sources or not. Mercury (Hg) is a common minor component in such systems. Hg isotopes undergo unique mass-independent fractionation (expressed as Δ 199 Hg values), which is mainly generated during Hg photochemical reactions on Earth’s surface and not affected by magmatic-hydrothermal processes, offering an excellent opportunity to trace metal sources in hydrothermal systems. We observed near-zero Δ 199 Hg values in wolframite (−0.10‰ to 0.08‰, n =11), and in skarn- (−0.17‰ to 0.12‰, n =48) and greisen-type (−0.12‰ to 0.10‰, n =11) bulk tin-tungsten ore from eight major ore deposits in South China. These values are identical to those of coeval highly evolved granites (−0.13‰ to 0.12‰, n =49), supporting that Hg in W-Sn ores were sourced from granite. However, sulfides (e.g., pyrite, chalcopyrite, arsenopyrite, galena, and sphalerite) in these deposits exhibit negative to near-zero Δ199Hg values (−0.42‰ to 0.09‰, n =124), which indicates a contribution of Hg and by inference other metals from both Precambrian basement rocks (Δ 199 Hg<0) and ore-related granites. The study demonstrates that multiple sources of metals were involved in the formation of the polymetallic W-Sn deposits, and further highlights that extraction of metals from basement rocks may be a critical control on the formation of economically important mineralization of base metal sulfides (e.g., Pb, Zn) in granite-related magmatic-hydrothermal systems.

Mercury is a volatile heavy element with no known biological function. It is present in trace amounts (on average, ∼ 80 ppb) but is not geochemically well blended in the Earth's crust. As a result, it occurs in extremely high concentrations (up to a few percent) in certain locations. It is found along tectonic plate faults in deposits of sulfide ores (cinnabar), and it has been extensively mobilized during the Anthropocene. Mercury is currently one of the most targeted global pollutants, with methylmercury compounds being particularly neurotoxic. Over 5000 t of mercury is released into the atmosphere annually through primary emissions and secondary re-emissions. Much of the re-emitted mercury resulting from exchanges with surface reservoirs is related to (legacy) human activities, such as direct releases. Understanding the dynamics of the global Hg cycle is critical for assessing the impact of emission reductions under the UN Minamata Convention, which became legally binding in 2017. This review of atmospheric mercury focuses on fundamental advances in field, laboratory, and theoretical studies, including six stable Hg isotope analytical methods, which have contributed recently to a more mature understanding of the complexity of the atmospheric Hg cycle and its interactions with the Earth's surface ecosystem.

Top marine predators present high mercury concentrations in their tissues as consequence of biomagnification of the most toxic form of this metal, methylmercury (MeHg). The present study concerns mercury accumulation by Guiana dolphins (Sotalia guianensis), highlighting the selenium-mediated methylmercury detoxification process. Liver samples from 19 dolphins incidentally captured within Guanabara Bay (Rio de Janeiro State, Brazil) from 1994 to 2006 were analyzed for total mercury (THg), methylmercury (MeHg), total organic mercury (TOrgHg) and selenium (Se). X-ray microanalyses were also performed. The specimens, including from fetuses to 30-year-old dolphins, comprising 8 females and 11 males, presented high THg (0.53-132 µg/g wet wt.) and Se concentrations (0.17-74.8 µg/g wet wt.). Correlations between THg, MeHg, TOrgHg and Se were verified with age (p<0.05), as well as a high and positive correlation was observed between molar concentrations of Hg and Se (p<0.05). Negative correlations were observed between THg and the percentage of MeHg contribution to THg (p<0.05), which represents a consequence of the selenium-mediated methylmercury detoxification process. Accumulation of Se-Hg amorphous crystals in Kupffer Cells was demonstrated through ultra-structural analysis, which shows that Guiana dolphin is capable of carrying out the demethylation process via mercury selenide formation.

PurposeFerronickel is irreplaceable in modern infrastructure construction because of its use in stainless steel production. This study explored the cost-combined environmental impacts of ferronickel production in China which is the largest producer and consumer of ferronickel in the world.MethodsLife cycle impact assessment was combined with life cycle costing analysis to assess the environmental and economic performance of ferronickel production in China. Both internal cost (e.g., raw materials, energy, transport, infrastructure, tax, and labor) and external cost (i.e., human health, ecosystem quality, and environmental emission) were considered.Results and discussionThe environmental burden of ferronickel production in this study was mainly attributed to the damage on resources and human health as endpoints caused by indirect processes, such as electricity supply, transportation, coke production, lateritic nickel ore acquisition, and coal mining. Carbon dioxide, mercury, particulates, methane, sulfur dioxide, nitrogen oxides, coal, and nickel ores were the substances pivotal for optimizing environmental performance. The total economic cost was 2734.8 $/t, of which 2333.3 $/t was internal cost and 401.5 $/t was external cost. Lateritic nickel ore, electricity, human health cost, and transport contributed 44.9%, 20.6%, 14.2%, and 4.8% to the total economic cost, respectively. The remaining economic burden was mainly divided to coke, coal, argon, labor, equipment, and tax.ConclusionsA win-win case for the environment and economy can be achieved by optimizing electricity and lateritic nickel ore quality, including its transport. Application of other power types (e.g., hydro, wind, and solar electricity) as a substitute for thermal power can also reduce environmental impacts considerably. Sites with high steel yield, low thermal power ratio, and high port proximity, such as Fujian Province, are the primary choices for ferronickel production. Finally, although the economic benefits of coke and coal are minimal, their efficiency in environmental improvement is crucial.

Artisanal and small-scale gold mining (ASGM) represents 20% of gold supply and 90% of gold mining workforce globally, which operates in highly informal setups. Pollutants from mined ores and chemicals introduced during gold processing pose occupational and inadvertent health risks to the extent that has not been well elucidated in Africa. Trace and major elements were analysed using inductively coupled plasma mass spectrometry in soil, sediment and water samples from 19 ASGM villages in Kakamega and Vihiga counties. Associated health risks for residents and ASGM workers were assessed. This paper focuses on As, Cd, Cr, Hg, Ni and Pb for which 96% of soil samples from mining and ore processing sites had As concentrations up to 7937 times higher than the US EPA 12 mg kg−1 standard for residential soils. Soil Cr, Hg and Ni concentrations in 98%, 49% and 68% of the samples exceeded respective USEPA and CCME standards, with 1–72% bioaccessibility. Twenty-five percentage of community drinking water sources were higher than the WHO 10 µg L−1 drinking water guideline. Pollution indices indicated significant enrichment and pollution of soils, sediment and water in decreasing order of As > Cr > Hg > Ni > Pb > Cd. The study revealed increased risks of non-cancer health effects (98.6) and cancer in adults (4.93 × 10−2) and children (1.75 × 10−1). The findings will help environment managers and public health authorities better understand the potential health risks in ASGM and support evidence-based interventions in ASGM processes, industrial hygiene and formulation of public health policy to protect residents and ASGM workers’ health in Kenya.