5 Best Spice Grinder with Prices on Amazon Stone Spice Grinder Tom Dixon Natural Onyx Mortar and Pestle Beautiful Round Marble Stone, Spice Natural Onyx Mortar and Pestle Beautiful Round Marble Stone, Spice Natural Onyx Mortar and Pestle Beautiful Round Marble Stone, Spice. The simplest of tools; use the pressure of your palm to roll the ball and pulverise your spices. Tested and approved by our London kitchen. Carved from solid blocks of marble with a marble ball. Ideal when paired with our Stone Pestle and Mortar. Diameter: 18cm Height: 13cm