The gold pan is the most basic tool for use in gold prospecting. Although construction
materials have changed over the centuries, the basic design, function, and method
of use has remain unchanged. The gold pan works by separating materials by density,
or specific gravity, whereby the more dense particles such as gold settle to the
bottom of the pan while the lighter materials on top are sifted off layer by layer.
Use of the gold pan is simple at its rudimentary level, but technique can take time
and practice to perfect. To begin, the pan is filled with paydirt from a suspected
gold-bearing area. Next, the pan is submerged in the water and agitated in a circular
motion. This turns the material into a suspended slurry which allows the gold to
drop to the bottom. Then the pan is tilted partially submerged in the water and moved
back and forth to remove the lighter material on the top. This process of slurrying
the material and removing the lighter top layer is repeated until the heavy black
sands and gold are all that remain in the pan.
Modern sluice boxes are usually made from aluminum or plastic that is molded into
a U shaped channel with a set of riffles and carpet in the bottom. The box is set
up in the course the stream with an even flow of water down the middle. Material
is fed into the box at the upstream end, and the water moves it progressively down
the box over the set of riffles. The gold, black sands, and other heavy components
settle behind the riffles and into the carpet due to the eddying effect of the turbulent
water and differences in specific gravity. When finished, the carpet and riffles
are cleaned out and the concentrates are panned out to recover the gold.
A power sluice, or highbanker, uses the same principle as the the hand sluice. It
adds efficiency to the process through the use of a hopper box where the material
is washed and screened, which allows the larger rocks to pass out of the system and
the smaller particles and gold run to through a sluice box. A water pump and hoses
are required, but water permitting, the unit can be moved directly to the work location
thereby eliminating the need to carry material long distances to a sluice box set
up in the stream.
The suction dredge is a relative newcomer to the prospecting world, having only been
used widely since the 1950s. The dredge is the ultimate gold-getting tool for recovery
of stream-bound placer gold, because it allows the prospector to actually work gravels
in the course of the active streambed. The dredge operates by forcing high pressure
water from a pump through a venturi which causes a pressure differential that is
harnessed with a suction hose allowing the prospector to literally vacuum the bottom
of the river. The material is then passed through a sluice box on the surface for
Metal detectors are another tool that the old-timers didn’t have available to them.
These units are able to locate gold by looking at a disturbance in a magnetic field
that is picked up by the search coil. Detectors are mainly of use in prospecting
areas that have potential for larger gold, such as river bedrock, hydraulic diggings,
and tailings piles due to the particle size that the machine can detect.