This piece is handmade from black clay, or barro negro, from the state of Oaxaca in southern Mexico. The black color is the result of a natural oxidation process, free of chemicals, lead, or glaze. The use of Oaxacan black clay to produce pottery dates back to Zapotec times, when it featured a matte grey finish. In the 1950's, a potter of Zapotec ancestry developed the beautiful patina seen today by burnishing the pottery before putting it in the kiln. This St. Frank piece has been fired at a high temperature, a technique used in the Oaxacan valley for centuries to reduce porousness and increase durability in Mezcal and water containers.