(ËlÉk tÉrn) n. 1. a reading desk in a church from which the Bible lessons are read during the service. 2. a stand with a slanted top, used to hold a book, speech, etc., at the proper height for a standing reader or speaker.
How a Diamond is Formed. In order for diamond to form there must be an available source of carbon and relatively narrow ranges of temperates and pressures must align. This happens around 100 miles below the crust. Once crystalized the diamonds must be rapidly transported to the surface without undergoing substantial change.
Diamonds form under remarkable conditions! 1  The temperatures are about 900 - 1300 C in the part of the Earth's mantle where diamonds form. 2  The pressure is between 45 - 60 kilobars. 3  50 kB = 150 km = 90 miles below the surface.  60 kB = 200 km = 120 miles below the 1  surface. Diamonds are carried to the surface by volcanic eruptions.