High Melting Points
Name: Jacquie H.
A student asks "Wouldn't it be impossible to gauge the
melting point of a diamond because it is so high, the equipment would be
destroyed in the process?" I discoverd the melting point is over 3800
Kelvin but have no idea how this was arrived at. Can you help us?
A very perceptive student!!! You are correct, the melting point of diamond
at atmospheric pressure is the highest of all known materials, so its
melting point must be measured under high pressure and the melting point at
atmospheric pressure calculated from thermodynamics, which is quite
reliable. At 1 atm the melting point is about 4000 K +/- ~200 depending upon
whose measurements you believe. However, the melting temperature drops to
about 1200 K at 600k-bar. Both of these conditions are attainable in the
You can find out the details at the following website. It requires Acrobat
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Update: June 2012