Chrysoprase, a light green variety of quartz, used as a gem. Its color is due to the presence of a small quantity of nickel oxide. Chrysoprase is translucent and fades when exposed to heat or light. The color may be restored when the stone is placed in a damp atmosphere. Chrysoprase is found in Europe, the United States, and Australia.
Ever since its discovery in 2000, a dinosaur fossil named Leonardo has held the interest of paleontologists the world over. A 3-D model of the animal even toured the world. So what's the big deal?
Sometimes dinosaur fossils are too large and heavy to display without damaging them. How are those enormous models built? And what makes them look so realistic?