here bs 
/ 
NE aks 
Discovery of Platinum in the Ural Mountains. 367 
olivine or olivine-bearing rocks (as in the case of the largest 
platinum deposits of the Urals), it might be considered as 
entirely probable that serpentine or some olivine rock 
formed the matrix in which the platinum occurred, and 
from which it found its way into the alluvial deposits. 
The very extensive platinum washings in the valleys of 
the Salda and the Tagil (both tributaries of the Tura, which 
in its turn is a tributary of the Tobul, which flows into the 
Irtys) occasionally afforded specimens in which the plat- 
inum could be seen intergrown with olivine or chromite. 
From an examination of the alluvial washings of the east- 
ern slope of the Urals, therefore, it was pretty certain that 
the platinum had been derived from the disintegration of 
serpentine rocks, although the metal was never found in 
place. Very recently, however, these probabilities have 
become certainties. 
About ten years ago, in the Krestovozdvizensky property 
belonging to Count Suvaloy, in the district watered by the 
rivers Vyzaj and Kaiva tributaries of the Kama, and on 
the western slope of the Urals, platinum was found in grains 
disseminated through the rock on which alluvial deposits 
containing platinum rested. This rock is an olivine gabbro. 
Another discovery has just been made in the Goroblagodatsk 
district, on the eastern slope of the Urals, where platinum, 
associated with chromic iron-ore, has not only beer found 
disseminated in an olivine rock, but has been found in such 
abundance that the rock can actually be worked with profit. 
Twenty-two grains of platinum were obtained from one ton 
of the rock, and although this result was highly encouraging, 
laboratory assays of other portions of the rock impregnated 
with platinum have given much higher results, in some 
cases as much as 93 to 110 grains of platinum to the ton of 
rock being found. 
