Stone characterization for wire cutting

Hardness tests and microhardness are currently considered as important methods for acquiring useful information about the workability of ornamental stones. The concept of workability refers to rock-cutting tool since at least thirty years and is the subject of national and international researches that aim to find a model for the prediction of the behavior rock-tool thanks to data coming from fast and inexpensive tests. In the present research 13 stones of different origin have been taken into consideration. These 13 stones have been classified by the plant owner within a scale from 1 to 10 based on the greater or lesser ease of cutting, established directly at the plant, where they were cut with a diamond wire. The parameters that have led to this classification are not known, but probably are connected with the yield in produced slab. It was therefore decided to find criteria for the classification of the stones themselves, based on parameters coming from simple laboratory tests, which may lead to a scientific correlation with the industrial classification. For each stone the following investigation techniques have been considered: petrographic analysis, highlighting mainly mineralogical composition, crystal size, structure and texture, microhardness, ultrasound pulse velocity. The results of all the tests performed have been elaborated and good correlations between them and the industrial classification have been found.