Querétaro de Arteaga (kārāˈtärō ħā ärtā-äˈgä) [key], state (1990 pop. 1,061,236), 4,432 sq mi (11,479 sq km), central Mexico. The city of Querétaro is the capital. With mountains in the north and valleys and plains in the south, the state raises a variety of agricultural products, especially grains. Extensive pasturelands make livestock breeding important. The state is famous for its opals; silver, iron, copper, and mercury are also mined. Although Querétaro is developing an industrialized economy, most manufacturing remains concentrated in the capital. The territory was taken from the Chichimecs by the Spanish in 1531, but colonization did not begin until 1550. Later included in the intendancy of Guanajuato, Querétaro became a separate state in 1824.