Some articles on rock, ultramafic:
... Andesite - an Intermediate volcanic rock Anorthosite - an igneous ultramafic rock composed predominantly of plagioclase Aplite - a very fine grained intrusive igneous rock ...
Famous quotes containing the word rock:
“Never before has a generation of parents faced such awesome competition with the mass media for their childrens attention. While parents tout the virtues of premarital virginity, drug-free living, nonviolent resolution of social conflict, or character over physical appearance, their values are daily challenged by television soaps, rock music lyrics, tabloid headlines, and movie scenes extolling the importance of physical appearance and conformity.”
—Marianne E. Neifert (20th century)