Pennsylvania Eastern Region Abstract Competition. The Wright Center for Graduate Medical Education (Formerly Scranton Temple Residency Program) in Scranton, PA will host the ACP PA Eastern Regional Meeting on October 6, 2012 at The Commonwealth Medical College (TCMC) in Scranton. The competition is open to all residents in the Pennsylvania Eastern Region.
Diamonds are formed as an allotrope of the element carbon, at depths greater than 90 miles. The pressure and heat at this depth is critical to the formation of the diamonds thâ¦at are mined at the surface today. At crustal pressures, the stable form of carbon is the allotrope graphite.
Gems Formed in the Earthâs Mantle. Knowledge of the earthâs mantle is still rather limited. However, the evidence shows that some gems actually form in the mantle. To do so, they need to crystallize at an extremely high temperature. The most notable examples of gems formed in the earthâs mantle are diamond and peridot. By studying the peridot deposits in Arizona, geologists now believe they were created on rocks floating in the mantle, approximately 20 to 55 miles below the surface. An explosive eruption brought them near the surface of the earth.