The problem of determining the total amount of heavy minerals in alluvial placers is considered, as well as the reasons that prevent the movement of heavy resistant minerals that are in mechanical mixture with alluvium. The regularity of the quantitative distribution of heavy minerals in alluvial placers is given that the State Committee of the Council of Ministers of the USSR for Inventions and Discoveries was registered as a scientific discovery under No. 127. The probability of occurrence of error signs during geological exploration in placer deposits has been considered. The book is intended for engineering and technical workers of geological exploration and production enterprises engaged in exploration and operation of placer deposits.