(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.
Technically, a diamond is an allotrope, or a form, of the element carbon (a diamond is actually carbon in its most concentrated form). Within a diamond, the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. This arrangement of carbon atoms essentially means that the diamond expands outward at the same rate in all directions during its initial growth. Because of its structure, which is extremely rigid, a diamond can be contaminated by very few impurities, such as the elements boron or nitrogen. Combined with its tendency to be transparent, this results in the colorless, clear appearance of most diamonds.