This paper addresses the two problems that arise in evaluating dimension-stone quarries: absence of a single quality variable and classification of blocks of stone. In constructing the single variable, an approach considering multivariate spatial relations of a number of variables that affect quality of dimension-stone is proposed. The multivariate spatial relations are defined by variogram matrices. In classification of the blocks, a decision analysis approach that rests on two key concepts, cumulative conditional distribution function and loss function, is introduced. The approaches are applied to an andesite quarry located in Ankara, Turkey: one level of the quarry is chosen to be a test area from which 108 rock samples are taken at 20m regular intervals. The rock samples are tested for some of the mechanical properties of andesite that control the economics of extraction process, and a quality index is produced using test data. The application area is then divided into 1862 5x5m square blocks, and the conditional distribution functions for these blocks are estimated by indicator kriging. Finally, the blocks are classified as exploitable and non-exploitable on the basis of minimization of economic losses.