382 A. W. Chase—Gravel Deposit of Gold Bluffs. 
the bed-rock or hard strata underneath the sand after it was 
stripped. It glittered with fine particles of gold, and I could 
then well believe the stories of the first discoverers. 
So exceedingly fine, however, is the character of this gold, 
that it requires a much larger quantity of these particles to 
reach the value of a cent than one not familiar with the sub- 
ject would suppose. Specimens of the sand as taken from the 
beach are presented with this paper. On microscopic examina- 
tion, besides the gold and magnetic iron ore, the sand will be 
seen to contain minute and brilliant red particles, which I be- 
lieve to be spinel in some of its forms. Other translucent 
particles will be seen. ; 
Prof. Silliman, in notes on the Mineralogy of California, 
Utah and Nevada, mentions a variety of minerals as compos- 
ing the black sands of Butte County. It is probable that all 
or nearly all of these will be found in the sands from Gold 
Bluff. “As there are large deposits of chromic iron in the 
county adjoining, it is probable that chromite forms a portion 
of the black sand. “ 
Prof. Silliman mentions syenite as the matrix from which 
most of the minerals he enumerates came. I present a small 
pebble of syenite from Gold Bluffs. It is a common factor m 
the gravel masses. 
peony well up on the bluff. When they saw a heavy 
reaker coming in they would face the cliff hke veterans, 
and, with firmly braced feet and drooping ears, allow tne 
water to dash over them; when the swell receded, off they 
would start again. During the time I was present these 
mules made three trips, carrying up on the whole some six oF 
seven tons: this was on a single tide. 
On arrival at the works the sand is deposited in an enclosure 
called the “sand corral.” A large lagoon near by supplies the 
neces fresh water for separation. small stationary 
engine and foree-pump is in use. The washing is done 1D 
machines called Long Toms, the gold being caught on copper 
lates which are charged with quicksilver. Formerly it is be- 
ieved that a large percentage of the gold, ground down as if was 
by the wearing action of the surf to a powder, was lost. Now 
_ the plates are first coated with a layer of silver before the met 
