. Carnegie Institution of Washington publication. 14 INFRA-RED REFLECTION SPECTRA. Pyrrhotite [(Fe, Ni)S]. (Massive. From Sudbury, Ontario. Curve b, fig. 6.) The specimen examined did not appear so highly polished as molyb- denite. It is composed of a bright metal and a darker background. The reflecting power is higher than that of MoS, and increases rapidly with wave-length through the spectrum of 14 /i. Chalcocite (Cu2S). (Curve c, fig. 6.) The reflecting power rises rapidly from 15 per cent at 1 /z to 45 per cent at 4 /*, while beyond 7 /j. the reflecting power has a fairly constant. 2 3 4
. Carnegie Institution of Washington publication. 14 INFRA-RED REFLECTION SPECTRA. Pyrrhotite [(Fe, Ni)S]. (Massive. From Sudbury, Ontario. Curve b, fig. 6.) The specimen examined did not appear so highly polished as molyb- denite. It is composed of a bright metal and a darker background. The reflecting power is higher than that of MoS, and increases rapidly with wave-length through the spectrum of 14 /i. Chalcocite (Cu2S). (Curve c, fig. 6.) The reflecting power rises rapidly from 15 per cent at 1 /z to 45 per cent at 4 /*, while beyond 7 /j. the reflecting power has a fairly constant. 2 3 4 5 6 7 a 9 10 11 12 13 Fig. 6. — Molybdenite (a); Pyrrhotite (ft); Chalcocite (c); CoveUite. /4/Z value of 55 per cent. This substance is black, not unlike magnetite and the Siberian graphite previously described. The polish was higher than in pyrrhotite. CJ COVELLITE (CuS). (From Anaconda Mine, Butte, Montana. Curve d, fig. 6.) This mineral is of a steel-blue color, and appears as compact as steel. The reflecting power rises rapidly at 1 and 2 // and then more slowly to 14 p., where it amounts to 75 per cent. As a whole, the examination of the sulphides shows that the sulphur atom has merely reduced the reflecting power of the metal, but has not brought about any bands of selective reflection in the region examined. In the case of sphalerite (ZnS) the sulphur atom has introduced into the metal a property which is to be found only in non-metals, viz, low re- flecting power and selective absorption in the infra-red. Of the elements which are on the border line between metals and non-metals, selenium behaves like a metal in its high reflecting power (see fig. 7) and absence of infra-red absorption bands, while iodine and sulphur (non-metals) have absorption bands in this Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble t
Size: 2207px × 1132px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1908
