I have a granite Mortar-Pestle, which I use to grind spices and other stuff. I got it 2nd hand and I've been using it for a 3-4 months. I have noticed that the small radial groves on the grinding surface of the pestel are slowly disappearing.
Do I need to re-grove the pestle? If so how is it done? I can't seem to find any information about that on the internet.