QUARTZ VEINS IN THE GOLD REGION. 
297 
they are very commonly called. We could see over a very considerable extent of the surface ot 
the hills east of us, and here and there, long, white, lines like walls of stone were visible. These 
were the outcrops of the quartz veins, trending, for the most part, parallel with the bedding of 
the metamorphic slates which they traverse. An outcrop near our trail formed a conspicuous 
OUTCROP,OF A GREAT QUARTZ VEIN. 
feature in the scenery. The great blocks ot snowy whiteness contrasted finely with the dark- 
colored slates on each side ; and, being little acted on by the weather, have accumulated in a 
long line, like a cyclopean wall, while the surrounding rocky foundations have mouldered away. 
This, and similar ledges of dense, vitreous quartz, are not favorably regarded in the gold 
region, for the very good reason that they seldom contain gold ; or if in small quantity, the 
labor of extraction is too expensive to be undertaken. 
Another great vein of quartz, near the road we followed, was rendered very interesting by its 
association with a very compact but hydrated peroxide of iron. This ore presents some remark¬ 
able peculiarities at this locality, and is described in another part of this chapter. It is probable 
that this ferruginous quartz vein is auriferous, but no gold could be detected by the eye. 
From this vein to the Mariposa river, we passed along the border of the gold region ; and an 
occasional quartz vein was seen. A great part of the ground that we passed over was highly 
colored with oxide of iron, and loose fragments of quartz were numerous on the surface. 
On the Fresno and San Joaquin rivers, miners were at work ; and a considerable quantity of 
fine scale gold was being removed from the alluvial drift. Between the San Joaquin River and 
Posuncula or Kern River, rocks of the auriferous series were seen at several places ; especially 
38 F 
