1864. | Anstxp on Copper Mining in Tuscany. 43 
The ore in the serpentinous vein is all in nodules. These vary in 
size exceedingly, but they vary little in appearance, and all probably 
have the same origin. They are masses of sulphide of copper and iron, 
the central part being the hardest and most ferruginous, and the other 
part containing the richest and purest copper ore. This outer part is 
often peacock ore, and sometimes grey sulphuret. Earthy carbonate 
of copper is rare, and malachite, or compact carbonate, quite un- 
known. Native copper is found, but only in small detached fragments 
(not crystalline) in the gabbro. No crystals of copper ore have been 
found—a fact sufficiently remarkable. 
The kidney-shaped, rounded nodules of ore are in some parts of 
the lode accompanied by a considerable quantity of equally rich ore, dis- 
seminated through the veinstone, and only separable by dressing. It 
has sometimes been thought that these rounded masses are water-worn, 
but this I greatly doubt. 
One of the first things that struck me when I visited the Monte 
Catini mine, and looked at the surrounding country, was the contrast 
it offered to ordinary mining districts in our own country, and the 
curious resemblance to what I had seen in Algeria, in the mines of 
Mouziia, in the Lesser Atlas. Here rich ores of similar nature have 
been found distributed in the same irregular manner in bunches com- 
municating by narrow threads. The veins range N.E. and 8.W., 
parallel to the mountain chains, and traverse altered tertiary rock, 
cretaceous limestone, and shale. The serpentine is there absent, though 
there are not wanting trachytic porphyries, representing those of 
Monte Catini. The fact that tertiary rocks are fractured to form 
veins in both cases, and the mode in which the veins have since been 
filled up, are not the only points of resemblance. 
Another remarkable instance occurs in the celebrated mines of 
Cobre, in Cuba, where rich and abundant copper ores are found in a 
district abounding with limestone. The rock containing the vein here 
consists, however, of a calcareous porphyry, passing into limestone on 
the one hand, and basalt on the other. The particulars of this curious 
lode I have described in the ‘ Proceedings of the Geological Society,’ 
vol. xiii. (1857), p. 240. The general bearing of the lode is east and 
west, parallel to the coast, and to the principal mountain ridges. 
To those accustomed to regard the great system of veins, the prin- 
cipal deposit of ore, and all the important modifications and trans- 
formations of rocks and their contents, as events altogether beyond 
recent geological times, these accounts of very important deposits of 
copper in modern calcareous rock and lavas of tertiary date, cannot 
fail to excite astonishment. In many respects the vein of Monte 
Catini is exceptional, but it is extremely suggestive, for it presents to 
us an example of recent metamorphic action of the most energetic kind 
connected with modern volcanic disturbance, so far as upheaval and 
fracture are concerned, but also indicating the presence and influence 
of water, by whose agency crevices, once formed by violence, have been 
subsequently filled up. The steady, permanent, and all-pervading in- 
fluence of water, producing now the same effects that it has always 
done, is perhaps nowhere more clearly exemplified than in Central 
