Jasper, an opaque form of quartz that contains iron oxide or iron hydroxide as an impurity. Jasper is usually red, brown, grayish green, or yellow. The stone is very hard and takes a high polish. It is used for inlays and for such ornamental objects as vases and decorative table tops. Showy or unusual forms of jasper are often used in jewelry. Ribbon, or riband, jasper is jasper in striped layers, or banded with rock crystal. Porcelain jasper is porcellanite, a dense, siliceous rock resembling unglazed porcelain. Brown or yellow jasper, also called Egyptian jasper, is usually streaked or clouded. Jasper occurs abundantly in veins and masses in many parts of the world.
In "The Raiders of the Lost Ark," Indiana Jones competes with grave-robbing Nazis for the lost Ark of the Covenant. But what defined Dr. Jones as legit and the Nazis as grave robbers?
Countless movies and television shows depict quicksand as some kind of living creature that sucks its victims down into a bottomless pit, never to be heard from again. Well, you can't believe everything Hollywood tells you.