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.
Everyone knows that once a bone has fossilized, it's hard as a rock, right? So how did scientists find soft tissue inside a broken dinosaur bone?
Earthquakes and volcanoes get all the press. But the landslides they trigger are often more devastating. What makes the ground suddenly rip downhill, taking trees and homes with it?