CHAPTER XX. 
METALS, ORES, AND MINERALS. 
Ores of iron.—Magnetite at the Canada de las uvas and Williamson’s pass.—Limonite.—Copper and its ores.—Copper py¬ 
rites.—Vein in the great basin.—Yitreods copper.—Native copper and red oxide of copper.—Sulphuret of antimony.—Descrip¬ 
tion of the VEIN AND ITS ASSOCIATION.—METALLURGY OF THE ORES OF ANTIMONY.—FURNACES.—LOCATION OF THE VEIN. LEAD. 
Sulphuret of mercury, cinnabar.'—Description of the ore and mine.—Furnaces for the extraction of the metal.—Gold.— 
Indications of gold along the route.—Quartz veins.—Placers near the san francisquito rancho.—Auriferous vein at 
Armagosa.—Colorado river.—Gold at port orford.—Crystalline gold.—Platinum and iridosmine.—Analysis.—Silver.— 
Telluret of silver, hessite.—Native arsenic.—Chromic iron.-—Emerald nickel.—Ilmenite.—Tourmaline.—Andalusite or 
macle.—Feldspar.—Bronzite or diallage.—Chrysotile.'—Gypsum.—Carbonate of lime.—Carbonate of magnesia.—Salt.— 
Carbonate of soda. 
The objects of the expedition did not permit of extended observations, at any great distance, 
on either side of the route explored. Mining localities, and veins of auriferous quartz in the 
southern mines, were passed by without my having any opportunity to examine them ; and it is 
doubtless the fact, that many other interesting mineral localities were passed, from time to time, 
in the hurried transits made from one field of operation to another. The following notices of 
interesting mineral veins, and localities of minerals, are of those that were incidentally met 
with in the course of the survey, or were afterwards visited or brought to my notice, and they 
are not to be regarded as an exposition of the mineral resources of California. 
IRON ORE—MAGNETITE. 
Canada de las Uvas .—Magnetic iron ore occurs in a vein about three feet thick, in a low ridge 
of white crystalline limestone, in the valley of the Pass known as the Canada de las Uvas. 
This ridge is near the highest point of the Pass, and the debris of the ore rolls down close to 
the trail. The vein, or bed of ore, is nearly vertical; its trend is nearly east and west, and 
the outcrop is traceable for about thirty feet. The ore is much, mixed with the carbonate of lime, 
but no other minerals of association were observed. It is compact, but not crystalline. When 
broken it shows a brilliant fracture, with a granular surface, and does not cleave, with broad, 
flat faces, as in the massive magnetic ores of New York and New Jersey. 
Williamson’s Pass. —Large rolled masses of magnetite were picked up in the bed of one of the 
streams entering the valley of Williamson’s Pass, on the east side. The ore is very pure and 
crystalline, and is associated with, hornblende, cinnamon-colored garnets, and chlorite. It 
probably exists in a considerable vein between the Pass and the Cajon ; and judging from the 
beauty of the minerals of association displayed even in the rolled fragments, the vein may be 
expected to yield specimens of interest to the mineralogist. 
Volcanoville, on the Middle Fork of the American River. —Large masses of magnetic iron-ore 
occur in a slight ravine, among boulders of quartz and other rocks, near the great vein of aurif¬ 
erous quartz at Volcanoville. Their source is not known, but it is probably in the vicinity. It 
must form & thick bed, judging from the size and number of the transported masses. 
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