The MINERALSCAN Model 1500 measures the natural radiation from ores and concentrates. A feature of many ores and associated rocks is that they usually contain trace amounts of potassium, thorium and uranium. Within any individual ore deposit, the absolute amount of these elements usually varies in direct proportion to the amount of different constituents of the ore. By using a sensitive detector, combined with careful screening of the detector to exclude other natural radiation such as solar and terrestrial radiation, the Natural Gamma Monitor can determine the concentration of the target elements with a suitable precision for many applications. The Monitor contains no radioactive source.
"... day to day, the operations rely on the Coalscan results"
Elsie Gretton, Boggabri Coal World Coal, Asia 2011