This paper deals with evaluating 3D-bootstrap for the mining company New Boliden in an attempt to revise their current method of calculating average gold riches in different areas. The purpose is to find one-sided 3D-bootstrap confidence bound of the average gold riches. There lacks well-defined theory behind using 3D-bootstrap, in this paper the variogram is used as an estimate of dependencies between the observations, and the block length is chosen to be higher than this estimate. In aid of this, a simulated data material is conducted to check the validity of 3D-bootstrap in a controlled area where the theoretical value is known. The results are inconclusive, and further studies are needed.