Geology Reference
In-Depth Information
apart of the supercontinent Pangaea (see Chapter 19). Some have been found in the very oldest rocks
of the continents (called the
craton
), and geologists think they were created back when the earth's in-
terior was much hotter, producing more explosive eruptions on the early continents. Still, only some of
these locations produce diamonds large enough to be gem quality, making them rare and valuable.
Scientists have created tiny diamonds in the laboratory by heating and compressing carbon-rich ma-
terials — but not coal. Synthetic diamonds such as these are used in dental drill bits and for industrial
uses (such as oil-well drilling) where the superior strength of diamonds is beneficial.
