A Comprehensive Treatise on Inorganic and Theoretical Chemistry

10 INORGANIC AND THEORETICAL. CHEMISTRY
surface-deposits, wore not swept away. They were concentrated later on in the
alluvia—perhaps at the time of the most intense glaciation, probably in the Pleistocene.
The basic igneous rocks, from which the platinum is derived, are exposed in the
form of discontinuous elliptical outcrops near the summits of the Urals, particularly
on the western side of the mountains. These outcrops attain larger dimensions in
the northern and central TJrals than farther south. The process of concentration of
platinum in the gravels has clearly extended over a very long period of time, and
it is probable that the richer gravels have been reconcontrated, perhaps several
times.
According to L. Duparo and co-workers, the deposits are essentially of magmatic
origin. The structure of the rock is in the nature of concentric bandings ; the felspathie
rocks at the outer edge grachially grade into the intermediate stage of pyroxenes,
until the central tlunite is reached, composed of olivine and chromite. The richness
of the gravels is in proportion to the size of the dunite deposits, and to the extent of
erosion of these rocks. Platinum ore derived from a pyroxenite source usually
contains high percentages of platinum and palladium, but low percentages of osmium
and iron. The reserves in 1916 wore sufficient for about twelve years, provided
that the same methods of working and rate of extraction were employed during that
period.
According to A. D. Lumb, platinum is concentrated in channels of the Rivers Iss, Veeya,
and Tura ; north of these, the metal is obtained from beds of the Rivers Sognovki, Kythymi,
and Mala Kosva ; and, along with gold, in the systems comprised in the Rivers Vagran,
Lobva, Niasma, Liabia, Aktai, Emorlo, Talits, and Ivdevi. In the south, platinum is
worked on the tributaries of the Rivers Tagil, Salda, Imiaura, and Tura. In the Nizhni -
Tagilsk district, the richest placers are iix the valleys of the Rivers Visim, Martian, Sisim,
Chaush, and Cherna, and farther south, along with gold, in the gravels of Nevian, Verkhne-
Isot, 13ilonibaov, Alapaov, Sysert. Kyshtym, and Mias, and in the Rivers Tanalyk, Sakmar,
and Urtazym. There are smaller deposits in Nikolae-Pavdinsk, Rastos, and Systersk.
The placer deposits are derived from country rock made up of serpentine gabbro, diallage,
and olivenite and the associated minerals are chiefly quartz, zircon, ilmenite, chromite,
magnetite, spinel, and native gold and palladium. The crude platinum usually includes
iridium, rhodium, ruthenium, and iron. A. A. Losch, A. Karpinsky, and A. Jvrassnopolsky
discussed the occurrence of platinum in Bissersk, -where a 2-kgrm. nugget of platinum was
found. In addition to what has been previously stated, the Ural deposits were discussed
by C. Blomoke, G. Rose, A. Inostranzeff, I. Koifman, A. G. Betochtin, V. P. Mishin,
G. Padalka, E. P. Moldavantzeff, P. P. Pihpenko, G. A. Dodonoff, A. Breithaupt,
A. N. Zavaritzky, J. «J. Berzelius, C Zerronnor, A. von Lasaulx, P. V. Jeremojeff,
G. Schuler, P. Iieyschlag and co-workers, A. P. Stahl, M. von Engolhardt, J. Podoroff.
L>. Serdyuchonko, and C. Hmtze vide supra. A. Solitander reported the presence of
platinum in the auriferous sands in the north of Filmland.
The occurrence of traces of platinum in the auriferous sands of the River "Ivalo, in
Lapland, was noted by A. K. Nordenskjold, 1 " and P. .T. Wiik, and at Vaske, and Tanna-Juk,
by J. H. Langer. The occurrence of traces of platinum in the nickeliferous pyrrhotitc of
Smaland in Sweden was discussed by J. H. L. Vogt, 17 L. de Launay, and P* M. Stapff.
J. H. Li. Vogt,* 8 and G. Lunde and M. Johnson also described the presence of traces of
platinum in the nickel ores of Norway ; and G. vom Rath, in the silver of Konigsberg.
J. PT. Vogel 19 roportod traces of platinum in Portugal. According to L. N. Vauquelni,^ 0
platinum occurs in Spain in the silver mines of Guadalcanal, Estremadura, although
J. J. Berzolius had doubts on this subject. A. Orio reported traces of platinum to be
associated with the pyrites of Asturia. According to A. D. Lumb, the metal lias also been
noted at Ronda, Malaga, in the alluvial deposits along the Rivers Verde and Guadaiza.
The deposits are derived from serpentine and peridotite rocks. The pay gravels contain
8 grms. of platinum per ton. The metal has also been reported in the other parts but
not in payable quantities. It occurs principally in the northern districts, and in the
Rivers Minho, Luna, SiI, Orbigo, Gallego, Cinea, Darro, and lower Jenil, where it occurs
in the concentrate sands accompanied by magnetite, ilmenite, zircon, and frequently gold.
S. P. de Rubies, K. Rubio, L. Duparc and A. Grosset, T. C. Earl, F. Gillman, and D. y Orueta
and S. P. de Rubies discussed the occurrence of platinum in Spain.
Asia.—The Uralian deposits in Asia have been indicated in connection witli the
Russian deposits. R. Helmhackor 21 reported the presence of platinum in the auriferous
sands of Altai ; and it has also been reported in Armenia—Batum and Sasun—by L. do
Launay, 82 but none was found by A. G. Betochtin in the peridotites of Gokoha. J. P. Kemp,
and N. Nakovnik reported it in Siberia—in Baikal, Balkash, and Jenissei. K. Jimbo, and
T. Wada observed that in Japan, the metal occurs in the auriferous sands of the province of
Ishakari, and the Yubari River of Iburi ; in the Rivers Yubari-garva, Pechau, and other
rivers in the province of Hokkaido where gold and iridosmium are associated with the
platinum. It is also found in the gold and iron sands of the Nishi-Mikawa, in the province
of Sado. E. de Hautpiek mentioned the occurrence of platinum in the auriferous gravels
in the Uryanchai district of Mongolia, on the Russian border of China. L. de Launay
found that the metal also occurs in the auriferous sands of Rigal, in the Philippines. Traces