In primary rock mass, with high intact strength and a small or null presence of open discontinuities, the rock mass strength depends on the volumetric distribution and mechanical properties of veinlets filled with different minerals. Vein properties can be used to obtain an index for rock mass characterization and classification into geotechnical domains, or they may be used directly in wedge analysis or in complex numerical models. A mineralized vein presents shear and tensile strength. These properties were measured, and the scale effect was approached by using 150 mm diameter samples for direct shear and indirect tensile tests. Vein properties were also obtained from triaxial compression tests in 48mm diameter samples. The test methods used are analyzed and the values of the mechanical properties of veinlets per mineralogy are given.