Do natural diamonds form from carbon-vapour or liquid-carbon

[B0b-A]

What is the state of carbon just prior to it forming a diamond, deep in the Earth's crust ?
Carbon vapour , or liquid carbon ?.Update: I think I've managed to answer my own question ...

http://www-als.lbl.gov/images/stories/Science_Highlights/Highlights/108carbon1.png
http://www-als.lbl.gov/index.php/holding/276-time-resolved-study-of-bonding-in-liquid-carbon.html But cannot manage to delete this thread

 

[Bystander]

Leave it, a reasonable C phase diagram is handy to have on the forum.