A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
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54 THE METALLURGY OF ANTIMONY.<br />
The principal antimony veins, in the neighbourhoods of Valongo,<br />
Paredes, and Gondomar, in the district of Oporto, may be roughly<br />
divided into two systems, according to the directions of their strikes.<br />
The one system has a strike, N. 10° to 20° W., coinciding with that of<br />
the country, and hence the deposits may be described as bed-like lodes ;<br />
and the system has a course N. 30° to 60° E. Both of these occur in<br />
Silurian rocks. Near the town of Alcontim, in the district of Faro,<br />
there occur two distinct lodes : one running E.-W. and the other N.W.,<br />
the latter of which has the same strike as the country. These occur<br />
in the slates of the Culm formation. Besides these localities may be<br />
mentioned Braganza.<br />
ALGIERS.<br />
The antimony deposits of Sidi-Bgheis are situated in the southwestern<br />
part of the province of Constantine, and have been mined at<br />
Sempsa and Djebel-Hamimat. They occur in the clays and limestones<br />
of the Lower Neocomian. The ore, according to Coquand, is in part<br />
a compact antimony oxide, and in part a granular crystalline variety<br />
containing senarinontite. At times the oxide deposits may be<br />
superimposed by bundles of stibnite needles. The deposits possess<br />
little gang no and are generally in the form of very irregular masses,<br />
parallel to the plane of stratification. According to Beck, they are<br />
impregnations (C), while de Laxinay classifies them under sedimentary<br />
deposits, and Coqxxand considers them to be contemporaneous with the<br />
enclosing rocks. (E.)<br />
At Djebel-Taia, stibnite is associated with cinnabar.<br />
TURKEY.<br />
At Allchar, in Macedonia, the antimony deposit is found associated<br />
with a great quantity of realgar, together with orpiment. The<br />
sulphur is undoubtedly derived from the decomposition of stibnite,<br />
and is the principal agent in changing many of the oxides intosulphides<br />
; while, together with oxygen, it transforms the neighbouring<br />
chalk into gypsum. This deposit is a good example of paragenesis.<br />
Other antimony ore localities are Adrianopolis, Monastir, Bozdan,<br />
Mytilene, Chios, Aidin, Eudemisch.<br />
SWEDEN.<br />
At Sala, in Westmannland, a small quantity of native antimony<br />
is found associated with the argentiferous lead ore It occurs in the<br />
primitive formations.