What do diamonds and coal have in common? They’re both made purely out of Carbon. But in terms of price, they could’t be more different.
It is known that diamonds are formed when Carbon is pressurized inside the Earth. We also know that the deepest parts of the ocean have a really high pressure. So could we use this knowledge to turn coal into diamonds?
The 4 statements below answer this question clearly with explanations.
Nope, it’s nowhere near enough pressure. The pressure at the bottom of the mariana trench is nearly 16,000 psi. The pressure required to make diamonds the natural way? 750,000 psi.
You’d have wet coal.
Despite being quite heavy, the ocean is WAY too little pressure to turn coal into diamonds.
For diamonds, we’re talking 237,000 to 1,300,000 atm. The bottom of the Mariana Trench, one of the deepest parts of the ocean, has about 1,070 atm.
So we don’t even need to get into the trouble of retrieving stuff from the deepest part of the ocean, because it’s just gonna be wet coal.
As something of an aside, most diamonds are not actually formed from coal. Much of the carbon that went on to form diamonds likely predates any of the living material that would form coal altogether.
If on the bottom of the ocean, the carbon is just “wet coal”, HOW DEEP of a (completely theoretical) ocean would be needed to provide the necessary pressure to form diamonds?
Pressure to turn carbon to diamond (assuming 1,200℃) is about 5,000,000,000 Pascals.
The density of water is about 1,000kg/m3 .
Gravity on our planet is about 10m/s2 .
The equation for the height of a column of a particular medium is defined by: h = P/ρg
h = 5,000,000,000Pa/(1,000kg/m3 )*(10m/s2 )
h = 500,000m = 500km
Diamonds, as found in diamond mines, are not now nor were they ever “made of coal”. Coal is a complex hydrocarbon. It does have a lot of carbon in it, but it’s got too much other stuff to ever simply be crushed into diamonds.
Diamonds are what you get from nearly pure carbon subjected to almost irrational pressures and heat, and they slowlycrystallize.
So pure graphite looks like a bunch of little hexagonal dinner plates. It’s all flat. A large flat sheet is this “graphine” you hear of. Then you just keep squeezing a whole stack of that from all sides and the little connections that make the array of dinner plates shape become an array of cubes with cross members to make diamonds.
That’s a lot of pressure. A lot of heat. And a lot of time.
Imagine trying to turn a stack of dinner plates into a brick just by finding something heavy to put on top of them. That’s just not going to work. The plates just break. So then you need to push them from all sides. Then you need to melt them to basically lava. Then you need to keep the pressure on until the lava becomes rock.
That’s a lot of heat and pushing.
The bottom of the sea is not as hot as lava. It’s not enough pressure. And if it was, the water would go between the plates and you’d never get your brick.
So coal is what happens if you burry a bunch of dead plants and get it sort-of hot under a bunch of pressure.
Diamonds are what you get when you crush pure carbon with a significant percentage of the earth’s heat and weight without letting it get mixed around.