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.
You Might Also Like
A sculpted mammoth shows visitors to the La Brea Tar Pits what these ancient animals might have looked like, but the pits themselves have looked the same for thousands of years. How did they form, and what discoveries lie beneath the sticky surface?
It's easy to trace the evolution of the automobile. Your family tree poses a whole different challenge. Even an extensive genealogy chart can only reach back so far. So how do we chart the evolution of the human race?