- 
cigs ata linge aaa 
82 W.P. Blake on the Gold Region of California and Oregon. 
Magnetic Iron Ore—A massive and fine-grained variety of © 
this ore is found associated with one of the auriferous quartz veins — 
of the county. Specimens that I have seen were colored green — 
by their layers of carbonate of copper. It has polarity and lifts 
small fragments. 
are Co.—Magnetic Iron Ore.—This ore occurs in a bed or — 
vein about three feet thick in a low ridge of white reba 
limestone at the summit of the pass known as the Cajiada de las 
U ore is compact but not crystalline, when role 
shows a brilliant fracture anda granular surface, and does not 
break with flat faces, like the massive magnetic ores of New — 
rack and New Je sey. ‘ 
w Pass—Magnetic Iron Ore.—Specimens of very pure and 
€ ystalline magnetite were picked up in the valley of this 
it is s associated with hornblende, :icieabacinamedtivad garnets 
: 
Placer CoN V ‘oleanovtlle. —Large boulders of compact mag- 
‘the bed of the creek that flows by the side — 
of the great vein of ‘auriferous quartz at that place. These boul- — 
ders are so large and abundant that it is probable a vein of ore — 
will be found iu sites in that vicinity | 
Sa 
and ¢ revices in the serpen- 
tine rocks of San Francisco are seat aiusy, with sm 
but brilliant octahedral crystals of magne di ‘not giv 
reactions for chromium when examined Bafor the blow 
Sulphuret of Iron.—Good crystals of pyrites are cbedinal n 
the talcose slates in various parts of the mining region. ‘At 
Georgetown, Placer Co., it is abundant in minute cubic crystals. — 
They are obtained free from rock or gangue as one of the prod- — 
ucts of gold washing, and as they are very brilliant and of un — 
form size they are worthy of a place in good collections. : 
Curomic 1ron.— Monterey Co.—Massive chrome ore of excel- 
lent quality was shown me in San Francisco and reported t0 — 
be from a short distance south of the Mission of San Juan. It isal — 
Sep he: fact that it is almost identical in its appearance with the — 
ore from “ Wood’s pit” in Maryland and like it, is partly covered — 
with pea coats and crusts of emerald nickel. ‘The extensive 
aMeiBation of this mineral in California has been noticed at 
length by Mr. P. 'T. ‘Tyson in his report.* 
Antimony.— Tulare Co.—A large vein of the sulphuret of an- 
timony, (antimony glance,) exists in the high granitic range that 
borders the Tulare valley on the south. It is about eighty miles | 
from e Angeles and is most readily visited-from the Tejon. BY — 
observations with the barometer, I found the outcrop of this vein 
to be at an altitude of abont 6000 feet above the sea. It is on the 
side of a precipitous ridge a granite and not favorably situa- 
ted for examination. [ts thickness was estimated to be ten feet 
* Ex. Doc., No. 47. Bist Cong., Ist Session. aver — 
