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The collection of minerals acquired by Mr. J. M. Spence 
during his residence at Caracas, and on several journeys 
along the coast, came from the provinces of Barcelona, Boli- 
var, Carabobo, and Coro, with a few obtained from the 
regions of the River Orinoco and Lake Maracaibo. The 
collection contains gold in quartz of very rich character, 
argentiferous ores, green and blue carbonates of copper, 
copper pyrites, galena, iron ores of various kinds, carbona- 
ceous minerals, calcites, silicas, and rock specimens of gneiss, 
mica, talc schists, kaolin, hornblendic rocks, and serpentine 
with a few imperfect fossil and silicified woods. 
The gold quartz of the richest kind, came from the Pro- 
vince of Guayana, where vast regions of auriferous rocks 
occur ; and where also gold is found in small grains, flakes, 
and nuggets of all sizes from an ounce to many pounds 
weight, in a clay from two to eight inches thick, as well as 
in a red peroxidated iron earth, both probably alluvial 
drifts. The quartz veins are richly impregnated with gold 
in crystals and strings, as may be seen in specimens in the 
collection. Other specimens of the gold rocks come from 
the Isle of Aruba, and Loro Estado, Tacasumino. 
The argentiferous ores are galenas and cupiferous, and 
are not of very great richness; they are from La Guaira 
Cumana, and Coro, where decomposed galenas are worked 
for silver. 
The copper ores include 20 specimens from mines that 
have been worked with profit, one of which, the Aroa mines 
in the province of Yaracui, is the most famous for the supe- 
rior richness of its carbonates. The specimen of cuprite from 
this mine or Quebrada has some long and beautiful crystals 
of olivenite with cubes of strontian, and from Aragua are 
specimens of pyrargyrite or red silver ore; others from 
Caracas, Coro, and the river Tui, include malachites and a 
native sulphate of copper, probably a crystallisation from 
the waters issuing from the mines. The chaleopyrites are 
