Specifies the procedure of treatment of crude samples and dried samples. The crude sample is intended for the determination of certain geometrical characteristics and physical and physico-chemical tests including moisture determination. The dried sample is intended especially for chemical tests. The principle consists in grinding followed by sieving of the sample until the whole mass passes through a 63 m mesh sieve. Subsequent mixing and drying. The dried dample is to be stored in an airtight container of such a capacity that it is almost filled by the sample.