House, please I need ideas on how to convert graphite to diamond. I am working on a project on this. Your ideas are highly welcome.

It's done with big pressure and some heat. You obtain "industrial diamonds" (search keywords), which are small and impure, but reasonably hard, so they can be used in cutting tools.

 

At an even smaller scale, nanocrystalline films of diamonds are routinely deposited with semiconductor processes, for instance as electron emittors, in attempts to make flat display screens.

You would require large setup to create high pressure and temperature. If it is a project planned do to at home, it is quite difficult. Why not change the topic to- Getting graphite from diamond. You get a big diamond and burn it!