Part of Grand Gallery.
A two-foot-long slice from a jadeite jade boulder provides a spectacular window into the dramatic process that formed this highly prized type of jade. This jadeite started as a small vein, or fracture, over 12 miles underground that was wrenched apart by the collision of two tectonic plates over 35 million years ago. During the shakeup, mineral-rich fluids rose into cracks in Earth's mantle and deposited jadeite rock. As the tectonic plates continued to rub against one another, the veins of jadeite broke and reformed again and again, producing the remarkable emerald green and white swirls. The polished 55-pound slab was recovered from northern Burma.