For a long time, metal detectors have been used to detect possible gold deposits. The prospecting task is similar to other prospecting techniques due to the experience and knowledge of the prospector is a key aspect to interpret the signals. Basically, a metal detector enables the gold prospector through the use of the most advanced electronic principles to study the earth, and rivers. In this way, the prospector investigates large areas to feel confident that he has uncovered a gold deposit. Essentially, valuable deposits may be detected through the use of metal detectors. Included in geophysical equipment are instruments for detecting conductive ores present in veins, lodes, pockets and placer deposits.
The detector is designed to provide in practical form a sound and usable metal and minerals detecting instrument. Essentially, the equipment detects through the use of induced electromagnetic fields, changes in the relative electrical conductivity of the material over which is carried. Conductivity is related to the ability of the material to conduct an electrical current. Since metallic ores are usually much more conductive than the surrounding soil or rock it is clear that they can be detected as conductivity changes if they are in the range of the instrument.
All metal objects may be detected since the instruments do not depend for their functioning on the magnetic properties of the buried materials. For these reason, all metals and conductive minerals including gold and silver can be found with equal ease. Native gold, silver and copper and the metallic sulphides are the material more appropriate for this method of prospecting. Some of the oxides such as magnetite is also detected due to is a good conductor. Gold prospectors do not need special knowledge or experience in order to operate a metal detector. Full and detailed instructions are usually provided with the equipment. Once the necessary tuning has been done, the unit will retain its sensitive adjustment even when operating over rough terrain or through vegetation. Only one person is required for efficient operation. All the instruments are highly portable for greater ease of operation and transportation.
When the area to be explored has been reached, the equipment is assembled and adjusted over ground that is known to be barren of gold bearing minerals. The equipment is carried over the suspected site. When the possible deposit is crossed, the instrument receiver will detect it by means of a loud buzzing in the receiving earphones as well as clear and sharply defined indication on the large visual panel. The depth to which the equipment will operate with efficiency is influenced by the metallic surface are of the deposit, the moisture content of the ground, the length of time where gold is located and the type of metal detector used. Consequently, a metal detector detects gold, silver and ear surface placer gold concentrations. The unit will not identify individual minerals, but will indicate the presence of metallic ore bodies within the depth range of the instrument and approximately outline the surface area of the gold deposit. Also, the equipment will locate local pockets in a barren vein, veins and rich placer deposits.