W. P. Biake on the Gold Region of California and Oregon. 77 
with brilliant crystals of white iron pyrites, and in other speci- 
mens the gold is entirely isolated from the sulphurets and is sur- 
rounded on all sides by the compact opaque quartz. Specimens 
of this character are sought after by jewellers and are cut and 
lished for ornamental purposes. n immense quantity of 
cimens for this purpose are mostly obtained from the placers, but 
‘some of the purest and most brilliant are procured from this mine. 
Nevada Co., Grass Valley—Gold Hill Mine.—Extraordinary 
specimens of gold in large smooth plates have been found in one 
of the veins of this mine. They traverse a semi-crystalline 
— 
Specimens that I obtained, have many interesting mineralog- 
ical peculiarities and appear to throw light upon the phenomena 
of the deposition of the metal. ai 
| ina form favorable for collection. 
- Tuolumne Co., Marble Springs (Merced River).—An inter- 
sting quartz vein at this locality bears plates of gold, iron py- 
rites, galena and zine blende. These mineral are abundantly dis- 
seminated in a compact gangue of white quartz and form beauti- 
ful specimens for cabinets. 
Placer Co., Volcanoville—This place is opposite Forest Hill 
on the middle Fork of the American river, and is noted as the 
locality of one or more very rich quartz veins. They occur trav- 
ersing slates in connection with erupted rocks and contain iron 
pyrites and free gold, disseminated in irregular masses. Speci- 
charged with irregular filaments and ragged masses ee 
ecomposition and discoloration of the vein and the adjoining 
slates rendered it so obscure that it remained unnoticed while the 
claim was worked asa placer mine. I had the satisfaction of 
