British gold coin first issued in 1663 when it was worth 20 shillings. It acquired a worth of 21 shillings in 1717 and was last coined in 1813. It was so-called because it was originally minted from gold mined in Guinea, Africa. Guinea is also derogatory American slang for an Italian-American from the late 19th century, which derives from the insulting term ‘Guinea’ which was first used to describe Negroes from West Africa during the 18th century. Much later, during the late 19th/early20th century, Italian-Americans were called Guineas because of their dark complexion.