The process of resource estimation of large precious metal deposits is illustrated by reference to major deposits now being mined or developed by Placer._x000D_
The estimation procedure commences with building an appropriate model of the mineralization and proceeds through steps of data validation and geostatistical studies. It is important that the geologists most familiar with a deposit be involved with all stages of the estimate, and also prepare a manual estimate used to validate the kriged resource._x000D_
Resource estimates are major exercises taking many man-months of work. The most time consuming part of this is usually construction of an appropriate three dimensional geological model._x000D_
The data base for the resource calculations must be complete and checked for accuracy. The most appropriate estimation method must be selected.