Columbia Encyclopedia

(Encyclopedia) bimetallism bīmĕtˈəlĭzˌəm [key], in economic history, monetary system in which two commodities, usually gold and silver, were used as a standard and coined without limit at a ratio fixed by leg...

(Encyclopedia) pyrite pīrīˈtēz, pə–, pīˈrīts [key], pale brass-yellow mineral, the bisulfide of iron, FeS2. It occurs most commonly in crystals (belonging to the isometric system and usually in the form of...

(Encyclopedia) coin, piece of metal, usually a disk of gold, silver, nickel, bronze, copper, aluminum, or a combination of such metals, stamped by authority of a government as a guarantee of its real or exchange val...

(Encyclopedia) Bonanza Creek, stream, c.20 mi (30 km) long, W Yukon, Canada. It flows NW to the Klondike River near Dawson. The first gold strike in the Yukon occurred there in 1896. ...

(Encyclopedia) Nadal, Rafael (Rafael Nadal Parera), 1986–, Spanish tennis player, b. Majorca. Widely regarded as the greatest clay-court player ever, “Rafa” turned professional at 15. In 2005 he won his first ...

(Encyclopedia) earring, a personal adornment, sometimes an amulet, worn attached to the ear lobe. Since prehistoric times the ear has been pierced for the insertion of the earring; certain primitive tribes distort t...

(Encyclopedia) Great Slave Lake, second largest lake of Canada, c.10,980 sq mi (28,400 sq km), Northwest Territories, named for the Slave (Dogrib), a tribe of Native Americans. It is c.300 mi (480 km) long and from ...

(Encyclopedia)  CE5 Colorado kŏlərădˈə, –rădˈō, –räˈdō [key], state, W central United States, one of the Rocky Mt. states. It is bordered by Wyoming (N), Nebraska (N, E), Kansas (E), Oklahoma and Ne...

(Encyclopedia) Nkrumah, Kwame kwäˈmā nkro͞oˈmä [key], 1909–72, African political leader, prime minister ...

(Encyclopedia) Copperbelt, mining region, N central Zambia, central Africa. A natural extension of the mineral-rich region of SE Congo, the Copperbelt is one of the richest sources of copper in the world. Cobalt, se...