Subject: What is found at the surface of diamond?

We learned that diamond is only made up of carbon.  The carbon atoms form a 
tetrahedral structure with four carbon atoms surrounding the central carbon 
atom.  If each carbon needs to have four other carbons to be stable what is 
found on the outer edge of the crystal structure?  In other words, how do the 
outside carbons reach stability if they don't have enough carbons around to 
form the octet?  thanks

Re: What is found at the surface of diamond?