Acting in Russia methodology of estimation and expert’s examination of calculated mineral reserves has been organized in the Soviet period, during development of the rigidly centralized system of the state planning and management. Since, 20 years there isn’t in the country any state monopoly (and financing) in the mining brunch and geological exploration. The new approaches are needed in procedure of estimating mineral reserves explored by the private enterprises. Anyway, functions, which the State Commission on mineral reserves (SCR) used to carry out in the Soviet time, remain nearly the same at present. Its full-scale authority, obligatory specifications are in clear contradiction with real economic relationship in the country. Computer modeling of ore bodies, composed on the base of geostatistical analysis of the exploration data, determines their natural contours and the ore grade distribution far more precisely than the formal index of the reserve’s category. There isn’t any necessity to approve in the SCR the so called group of the ore deposit complexity, nor the Technical-economic validation of limiting conditions. The mere procedure of the state approval of explored ore reserves ought to have the record keeping character.
On an example tin orebodies sites with various degree of concentration of useful components are considered. It is offered to consider ore columns and sites of the lowered concentration of metal within the limits of the uniform approach, allocating «concentration heterogeneity» on a basis meterpercent. Thus it is necessary to consider character of change of fault surface behaviour with depth depending on type of tectonic infringement.