ABSTRACT: In this study, use of Rock Quality Designation (RQD) and Volumetric Joint Count (Jv) parameters forprediction of block volume from Harşit Granitoid exposed in Dogankent (Giresun) area, was investigated.For this purpose, a quarry was chosen as the study area and properties of discontinuities were determinedby performing scan-line surveys on the pit slopes. In prediction of block volume from Harşit Granitoid, Vbwhich is an input parameter of Rock Mass Index (RMi) system, was used. Jv and RQD variables used forpredicting Vb value were defined from the discontinuity spacing measurements performed on differentslopes within the quarry. When considering the Block Shape Factor (β), the blocks can be generallyclassified as “compact, slightly long-flat” shaped. Due to some constrains of RQD, use of Jv values is more effective for predicting block volume. It was concluded that, the average producible block volumefrom Harşit Granitoid was determined to be Vb= 7.15 m3 and this value is within the range of theeconomically producable block volume.