Of the chemical elements shown on the periodic table, nine – carbon, sulfur, iron, copper, silver, tin, gold, mercury, and lead – have been known since antiquity, as they are found in their native form and are relatively simple to mine with primitive tools. Five more elements were known in the age of alchemy: zinc, arsenic, antimony, and bismuth. Platinum was known to pre-Columbian South Americans, but knowledge of it did not reach Europe until the 16th century.