Native arsenic

Fliegen-gift, n. fly poison, -holz, n. quassia wood, -kobalt, m, = Fliegenstein. -leim, m. fly glue, -papier, n. fly paper, -pilz, m. — Fliegenschwamm. -pulver, n. fly powder, -schwamm, m. fly agaric, fly amanita (Amo-nita muscaria). -stein, m. native arsenic. 

Gift-jasmin, m. Carolina jasmine (Gelsemium sempervirens). -kies, m. arsenopyrite. -kobalt, m. native arsenic, -kraut, n. poisonous plant, -kunde, /. toxicology, -lattich, m. strong-scented lettuce (Lactuea virosa). -lehre, /. toxicology. 

Scherben-kobalt, -stein, m. native arsenic, Schere,/. scissors, shears cutter notch, nick ... 

The difference in mineralogy of the Kuroko and present-day back-arc deposits are (1) metastable phases such as native sulfur, wurtzite, and amorphous silica are poor in the Kuroko deposits (2) arsenic minerals such as jordanite, tetrahedrite-tennantite, native arsenic, and realgar are common in the present day back-arc deposits (Okinawa Myojinsho Knoll Caldera), but rare in Kuroko deposits except tetrahedrite-tennantite (3) secondary minerals such as cerussite and covellite are common in present day back-arc deposits (e.g., Okinawa, Myojinsho Knoll Caldera) (4) Dendritic texture is common in the present day back-arc deposits. 

Spherulite formation by geometrical selection may rarely be seen on crystals with isotropic Habitus. Native arsenic. As, occurs in a confeito-like form, and is a type of spherulite grown through the geometrical selection of rhombohedral crystals. Spherical aggregation of calcite crystals with nail-head Habitus is also observed. Semi-spherical aggregates of platy barite crystals known as desert rose are shown in Fig. 8.6. 

A massive form of native arsenic having a fibrous foliated structure occurs in Saxony and Chile and is known as arsenolamprite (Gk. Aa/m-po s =lustrous). It differs from the ordinary form in possessing a brilliant lustre it is lead grey in colour, has density 5-3 to 5-5 and hardness 2. The following are analyses of samples from the above two sources ... 

Compounds of arsenic are extremely widespread. The black crust often found on native arsenic is a mixture of arsenic and arsenious oxide, AsaOs. This oxide frequently accompanies other arsenical minerals and occurs in two crystalline varieties, arsenolite (cubic), usually as minute octahedra in capillary crystallisations or in stellar aggregates, and claudetite8 (monoclinic), in thin plates resembling selenite. Both forms are lustrous and may be transparent to translucent, colourless to white. 

Preparation.—The element is used only to a small extent in commerce. None at all has been produced in recent years in the United States, where the annual demand rarely exceeds 100 tons.5 In Europe it is generally produced by the sublimation of native arsenic or by heating arsenopyrite or lollingite. The mineral is heated in the absence of air at 650° to 700° C. in earthenware retorts or in tubes laid horizontally in a long furnace. The arsenide minerals decompose thus ... 

Native Arsenic—Compounds of Arsenic—Tables of Minerals Containing Arsenic —The Ubiquity of Arsenic. 

Magnusson (34) pointed out that the occurrences of native metals in these veins probably were caused by oxidation of the sulfides by the manganese oxides. Furthermore, Mason (35) pointed out that the formation of native lead and pyrochroite took place in neutral, or more probably, in alkaline solutions. Similar conclusions were reached by Bostrom (8) as indicated by Figures 2 and 3, native lead, native arsenic, pyrochroite, and hydrocerussite probably form stable assemblages at fairly high pH values and reducing conditions. As far as can be deduced from... 

Bennett, B. and Dudas, M.J. (2003) Release of arsenic and molybdenum by reductive dissolution of iron oxides in a soil with enriched levels of native arsenic. Journal of Environmental Engineering and Science, 2(4), 265-72. 

Dudas, M.J. (1987) Accumulation of native arsenic in acid sulphate soils in Alberta. Canadian Journal of Soil Science, 67(2), 317-31. 

Although native arsenic, bismuth, iron, and other elements are known, they are not common. For commercial purposes, these elements are derived from more common, more complex, natural compounds. 

Palache et al, 1944), from the oxidation of native arsenic (Clark, 1970 Palache et al., 1944), and from the weathering of scorodite (Eckel, 1997). They are often intimately associated with each other (Dana and Ford, 1949). 

Claudetite and arsenolite are products of weathering of several arsenic sulfide minerals, of native arsenic, and of scorodite. 

Native arsenic is stable only under strongly reducing conditions and although it appears as a stable phase under standard state conditions, field observations indicate it only forms under hydrothermal conditions. 

God, R., and Zemann, J., 2000, Native arsenic - realgar mineralization in marbles from Saualpe, Carinthia, Austria Mineralogy and Petrology, v. 70, p. 37-53. 

Paronikyan, V. O., and Matevosyan, A. S., 1965, Native arsenic from Amas deposits of Armenian S.S.R. Doklady Akademii Nauk Armyanskoy, v. 41, p. 240-243. 

Sergeyeva, R I., Khodakovskiy, I. R, and Vernadskiy, V. I., 1969, Physiochemical conditions of formation of native arsenic in hydrothermal deposits Geochemistry International, v. 6, p. 681-694. 

To determine the stability of natural arsenic compounds in petroleum, various crude oils which had been analyzed previously by neutron activation were reanalyzed. These crude oils were stored in glass vials and bottles. Table 2.V shows the results of this study. Two sets of analyses were made, 15 months apart, and no significant changes in the arsenic concentration were observed. This suggests that crude oils containing native arsenic can be used as reliable standards for arsenic. 

The precision of the method was established by repetitive analysis of crudes that contained native arsenic and crudes to which known amounts of arsenic, as triphenylarsine, had been added. Both peak height and peak area measurements were made. The results are presented in Table 5.III. The relative standard deviation over the 10-100 ng As/g concentration range is 22% for the peak height measurement and 32% for the peak area measurements. Since better precision was obtained by peak height measurements, it is recommended that this measurement be used in preference to peak area measurement unless selenium is present. 

Native arsenic Wikimedia Commons in the public domain. Author Aram Dulyan. http // commons, wikimedia. org/wiki/File Native arsenic.jpg... 

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