In geology, eduction is a process in which the Earth crust spreads sideways, exposing deep-seated rocks.

It is prominent in middle layers of the Himalayas

Himalayas

The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...

, where gravity pushes the mountains down. Together with a high grade of erosion, this activity brings deep rocks to the surface, many from more than a depth of 100 km. The unusually fast elevation preserves rare metastable minerals, e.g. diamonds and coesite

Coesite

Coesite[p] is a form of silicon dioxide SiO2 that is formed when very high pressure , and moderately high temperature , are applied to quartz. Coesite was first synthesized by Loring Coes, Jr., a chemist at the Norton Company, in 1953. In 1960, coesite was found by Edward C. T...

.