34 NEW ALMADEN CINNABAU MINE. 



In connexion with the Santa Clara valley may be 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 tlie 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 



