Cairngorm, (also called Scottish topaz or smoky quartz), a smoky, yellow-brown variety of quartz. It is named for the Cairngorm Mountains of Scotland. The stone is highly prized in Scotland and is used for various ornamental purposes. Its value depends on transparency and shading. The mineral has been found in Great Britain, Siberia, Spain, and Switzerland, and near Pikes Peak, Colorado.
Before the existence of radiocarbon dating, archaeologists would hope their prized potsherds happened to lie buried next to a dated coin. How has the measurement of C-14 and C-12 revolutionized the science of archaeology?
Scientists believe that water pressure kept many dinosaurs from swimming. But does that mean that none of these massive animals took a prehistoric skinny-dip?