Natural sharpening stone From Lombardi, Italy. The quarries of Lombardi are know to produce some of the world best natural sharpening stones. The natural Lombardi stone has been recognized since the 15th century for its outstanding sharpening qualities due to its perfect, uniform balance of quartz and carbonates. Use the Opinel 4-inch natural Lombardi sharpening stone with water. MADE IN ITALYConstruction: Lombardi Natural Stone.Size: 4" x 15/16 x 3/16Weight: 1.3 oz