How It Works

Is it possible to melt diamonds?



If you heat diamond in the open air, it will start to burn at around 700 degrees Celsius (1,292 degrees Fahrenheit), reacting with oxygen to produce carbon dioxide gas. Heating diamond in the absence of oxygen, meanwhile, will see it transform into graphite – a more stable form of carbon – long before turning into liquid. Despite this, scientists found a way to melt diamond. Using super-strong magnetic fields, they fired small plates at 34 kilometres (21 miles) per second towards tiny pieces of the mineral, subjecting them to 10 million times normal atmospheric pressure. The diamonds melted, then re-solidified when the pressure dropped, leading some scientists to suspect there could be seas of liquid diamond on Neptune and Uranus, due to their atmospheres generating intense pressure and containing carbon.

Answered by Rik Sargent

  • Doug Chaney

    I KNOW this has to have already been mulled over, debated or even tried already but now that I understand that it is claimed to be not only just possible to melt diamond and then have it solidify again, but that it also HAS been done, already, then it seems reasonable for me to suspect that there is a possibility of making large ultra valuable hunks of diamond from say a whole bunch of nice quality but relatively worthless (compared to the “good stuff”, tiny diamonds (and or why not chips?or even dust? left over as the bi-product of the gem “cutting”processing of large stones??

    Surely someone has looked/is looking at this! Can it be done in theory? Or might it be the case that for some reason desirable diamond could not exist in this manner? Or else maybe it would be astronomically expensive to create the process on large enough scale? I am so curious!

    • aandrew132

      well sure it’s possible, but reading this, it seems that it would be financially infeasible to do this with current technology and known methods on a mass scale. they do this in special machines right now which can only manage to do it with tiny tiny amount of diamond.

      if we could manage to mass produce diamond disc like we to silicon discs for computing, then we would be at the next step of computing as silica is at it’s material limit in terms of what we can do with it with computing.

      it seems the problem they have is diamond turns into graphene if it’s not heated fast enough, and if oxygen is present, then it simply burns away like coal.

      perhaps if we could get diamond in a super vacuum, where boiling points are far lower for all materials, then maybe we would be able to heat it fast enough or in the right way that we could et it to melt without it changing to graphite or burning away. then again, i could just be an idiot and have my whole thought process be erroneous.

    • Jory Ferrell

      It is not as cost effective as vapor deposition. With vapor deposition, you heat a material (graphite in this case), and it naturally binds to the substrate, forming the lattice. The magnets required for the rail-gun are extremely power hungry, require huge amounts of maintenance, and don’t necessarily always result in pieces colliding to form a desirable diamond. With vapor deposition, you have much more control over the structure as it’s forming, and it’s guaranteed to form, with less hassle to boot.

  • Andrew Sparkes

    If a liquid state can be reached it follows that a gaseous state should theoretically be attainable. Perhaps in Some form of plasma. Therefore you could vapourise diamond dust/fragments and return them first to a liquid and then a solid. All in all an interesting intellectual exercise likely costing far more than any perceivable benifits. Although a diamond coating could have many uses.

    • Jeff Hamilton

      If there is a cost efficient way of performing this procedure, can somebody let me know?

  • Mahesh Doshi

    I am very curious about this subject… Please post some one has a knowledge about melting diamonds or at least surface of the rough diamond.

  • Rabdak

    Thinking…make a sun probe out of diamond. Shoot it towards the sun, see what lies beneath.

    • Alexander Vazquez

      the diamond would melt…