The uneven dimples are concave, have a big surface and are not very deep so that nothing remains stuck on the sides. The edges of the dimples are sharply polished which additionally facilitates the friction process. Ceramic is very fragile and is therefore used only at the bottom of the pestle and for the mortar’s core areas. All other parts are replaced by silicon. The adjustment according to the rules of an icosahedron allows for the regular allocation of dimples. Additional extra: certificated for contact with food.