According to DeBeers, a .2 gram diamond was formed from 2.8 grams of pure carbon.
So, 1/14th.
Where does the rest of the carbon go?
If it's anything like sapphire, it doesn't go anywhere. The atoms all line up in perfectly straight lines, and the mass is in fact stored as energy bonding the atoms so rigidly.
I am unsure of the physics involved here, because diamonds don't explode when you crush them. Of course, what you're really doing is just making smaller diamonds, so I guess they wouldn't.
That makes no sense at all to me, but I haven't taken physics and I only have four terms of chemistry.
Thing is, I'm not an actual material science geek. I'm a technician. I don't understand it, either.
Changing the chemical bonds won't change the mass. That's one thing I know for sure. Making and breaking bonds never changes the mass of an element. The mass of a quantity of pure carbon is determined solely by how many carbon atoms are present.
See, I don't know. I DO know, though, that to make 4 cubic cm of sapphire, weighing .3 kg, you need 1 kg of high purity alumina. I was led to believe that the high temperatures involved caused the mass to be used up making bonds, and I was obviously misled. Where does it actually go? NO IDEA.
Perhaps that is the amount of usable sapphire product after processing.
Naw, sapphire manufacturers are like proper Scotsmen. "NOTHING GETS WASTED 'ROUND HERE." The RF pots they use to attain 3500C are like never-ending stew pots, but they are measured between each batch, so the amount actually used is known. Also, I asked a friend of mine over there what the LOI mass loss was, and he said it was about 3-5%.
I have also been digging on the DeBeers thing. Nobody knows how much - if any - wastage happens during the natural formation of diamonds, but apparently the numbers they gave for synthetic diamonds are net numbers.