34 
NEW ALMADEN CINNABAR MINE. 
In connexion with the Santa Clara valley may he described the quicksilver mines of New 
Almaden, a village situated among the lower hills of the Santa Cruz mountains, about twelve 
miles southwest from the town of San Jose. To reach the mine a road leads from the valley, 
entering a chain of low sandstone hills which form the edge of the Basin valley, behind and 
above which the town and mine is situated ; the “ hacienda,” or works with the furnaces, are 
near the town, which is about 400 feet above the valley—950 feet above the hacienda is the 
mine. The mountain mass in which the latter lies is of serpentine with chloritic and talcose 
slates. Seams of limestone occur intercalated in threads, and masses of metamorphic limestone, 
twelve feet thick, occur on the ascent, before the serpentine is reached; the limestone is whitish, 
semicrystalline, and without fossils. The trend is northwest and southeast, which is also the 
direction of the metalliferous veins, (if this term be appropriate ;) the dip is variable in inclina¬ 
tion, but always to the east. The ascent to the mine is by a steep winding road 6,000 feet long. 
The mine is of comparatively old date, having been worked by the Spanish and Mexican 
settlers, and opened originally by them. Traditions are current of the Columbia river Indians 
having wrought there. Stone hammers and chisels of basalt, and aboriginal skeletons, have 
been taken from the openings made in the early diggings, which lie 100 feet above the scene of 
present operations. Doubtless the old site was pitched upon, as the ore crops out in its imme¬ 
diate proximity. 
The entrance to the present mine is by a long tunnel, about eight feet wide—the width of the 
vein ; this is cut in the serpentine and talc slate, which is here intruded on and altered by trap. 
The talc slate is the most abundant rock, but the serpentine and trap are associated with it in 
the mine. The water which percolates through the roof and sides of the tunnel deposites car¬ 
bonate of magnesia in amorphous white incrustations on its floor. The tunnels extend several 
hundred yards into the hill and then diverge in nine different directions, as the ore is found in 
pockets in the vein, and not in a continuous or regular seam, hence the working turns some¬ 
times suddenly round and upwards, so as to run in another exploration. On the sides of the 
adit the cinnabar may be seen intermingled in the trap and serpentine, and some decayed por¬ 
tions of this rock removed yield 10 per cent, of ore. The diffusion is in the serpentine rock, 
the trap is the metalliferous vein rock—the average yield of which is 20 per cent. When a 
pocket, however, is tapped, the ore is considerably purer, running up to 80 per cent., and an 
average of the whole yield of the mine would be 50 per cent.—the extremes being from 25 to 72 
per cent. One hundred tons are removed weekly by the miners, who are native Californians 
and Indians. It is removed in trucks running on a tramway along the tunnel from the gallery 
to the sorting yard. The sorting is performed in the usual way by the hammer. Women as 
well as men being employed, the latter chiefly carrying the sorted ore into heaps and packing 
the mules with baskets of sorted ore to be carried down to the hacienda. On account of the 
steep descent, the sure-footed mule is preferred to the horse, and a load of 70 or 80 pounds is 
placed in each basket, on either side of the beast, which constitutes its ordinary burden. The 
delivery of the ore might be accomplished more effectually by taking advantage of the descent, 
and employing one or more “chutes” instead of quadrupeds or sometimes Indians, as formerly 
occurred ; a wagon and horse has been recently introduced. 
The gangue stone associated with the cinnabar is quartz, forming geodic cavities ; sulphate 
of barytes occurs crystalized in some seams—the sulphuret is found in masses, toward which 
the quartz veins lead ; thus the thin and thready part of the vein may be found filled with 
