Comparative study of ornamental granite cleaning using femtosecond and nanosecond pulsed lasers

► The efficiency of femtosecond laser in removing biological crusts from granite is analyzed. ► A comparison with nanosecond pulsed laser efficiency is also presented. ► The efficiency in removing the crust is similar between both domains (femto and nanosecond). ► Microstructural features on silicates after cleaning reveals less thermal effects of femtosecond laser.