FIELD: geological ecological and process examinations. SUBSTANCE: method includes taking off weighed portion of source sample of object being examined. Weighed portion is ground, mixed with liquid and separated into heavy and light fraction gravitationally. Analytic weighed portion is taken from fractions for examinations. Weighed portion is ground up to size of less than 1 mm. For gravitational method use is made of inclined moving working surface with obstacles positioned along its edges. In process of classification light fraction of source material is drained from working surface, and heavy fraction is accumulated at its lower part near obstacle. Method enables use of large weighed portions of source sample (of more than 1 kg). EFFECT: enhanced accuracy and sensitivity.
