54 RESOURCES OF CALIFORNIA. 
into the river, with.a little gold. A thousand such gullies, 
contributing each a little gold, make a river rich. The heay- 
ier particles are deposited in the middle of the river-bed ; many 
of the smaller particles are deposited at the sides. The richest 
spots in gullies are usually where the bed-rock is full of crev- 
ices, as where slate, with perpendicular strata, crosses the 
gully. In those parts of a gully where the bed is very steep, 
there is usually less gold than in spots nearly level. In rivers, 
the richest spots are usually just below cafions, where bars are 
formed. Wherever there are eddies at times of high water, 
there the gravel, clay, and gold will be deposited; and when 
the river falls, a bar is exposed. The richest bars of California 
have been found at the mouths of cafions. 
§ 39. Mineralogy of Gold—tThe particles of gold in quartz 
are usually very rough in shape, but sometimes they are in 
octahedral crystals, and at others in smooth, leaflike sheets. 
Very rarely: specimens of crystals are found, clustered together 
so as to resemble pieces of coral. 
Placer-gold, called “ gold dust,” is fine and coarse. 
The fine is in scales, grains, flour, shot, and wire. 
Flour-gold is very fine dust. 
Grain-gold is in particles about as large as the end of a pin. 
Scale-gold is in scales from a sixteenth to an eighth of an 
inch across, and as thick as heavy wrapping-paper. 
Shot-gold is in roundish particles, the size of a pin-head. 
Wire-gold is in small wires, from an eighth of an inch to an 
inch long, and as thick as a pin. Sometimes the wires are 
fluted, or hollow on one side; and sometimes they are knotted 
together. 
Coarse gold is coarse-shot, pea, bean, moccasin, cucumber- 
seed, pumpkin-seed, large wire, and miscellaneous coarse. 
The pea, bean, cucumber-seed, and pumpkin-seed varieties 
of gold, have particles resembling in shape the seeds whence 
they derive their names. The coarse-shot is in particles re- 
sembling coarse shot in shape and size. Moccasin-gold is in 
pieces resembling a low shoe or moccasin in shape, and about 
