448 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 64 



1000 r 



SOLID III 

 (metallic) 



PRESSURE 

 (KILOBARS) 



1000 



2000 



GRAPHITE 



3000 4000 



5000 



T rK) 



Figure 4. — Phase diagram for carbon. 



in figure 4 and dream of the time when we can attain the presently 

 unattainable areas of temperature and pressure. Perhaps carbon will 

 assume a new form harder than diamond. In any event, crystal- 

 lographers can conceive of atomic arrangements which might put 

 carbon atoms even closer together^ — and more firmly bound — than they 

 are in diamond. The result might be^ — who knows ! 



