Diamonds Aren't Made From Coal. So Why Does Everyone Think They Are?

Aug 30th 2021

Diamonds Aren't Made From Coal. So Why Does Everyone Think They Are?

“A diamond is a chunk of coal that did well under pressure,” or so the saying goes. This old adage has probably been used to inspire a person or two to reach for diamond status, but there’s just one problem with it - A diamond isn’t a lump of coal that did well under pressure.

Why, then, do so many people think diamonds are made from coal? What is the source of this misinformation? Is there any truth to the myth? With a little digging, we might just be able to get to the bottom of this mystery.

Quoting Henry Kissinger 

You don't have to do much research to find the alleged source of the quote in question. Almost every online source gives Henry Alfred Kissinger, a Nixon-era U.S. politician, credit for the saying.

Of course, the quality of said sources makes the attribution seem specious. The sites which attribute the quote to Kissinger lack authority and are far from reliable news sources. Not only that, but these sources don't even provide context for the quote.

And if Kissinger didn't unleash this beast of a proverb out into the world, he can always give us a call to set the record straight. Whether or not he actually ever said the words, however, is technically a moot point for the purposes of our discussion. Kissinger is the universally agreed upon voice of the wisdom espoused in the quote, so we'll have to content ourselves with that fact—at least for now.

In any case, Kissinger's adage, while motivational, was factually incorrect when he supposedly uttered it years ago, and it's still wrong today. No one can say for sure that he knew this at the time, but we can all say that the saying has certainly become a real gem of its own, pun intended.

So, Do Diamonds Share Any Properties with Coal?

As we indicated before, Kissinger's motivational proverb has no factual basis. Despite that fact, we must admit that the saying at least tries to understand how diamonds actually form.

That is to say, diamonds do share some properties with coal, albeit not extremely significant ones. In order to understand these similarities a bit more, we'll briefly discuss how both coal and diamonds form beneath the surface of the earth.

How Is Coal Formed?

Like diamonds, coal forms deep underground under high pressure and high temperatures. The similarities between the two substances, though, pretty much end here.

Coal is a primarily carbon-based mineral substance, emphasis on the term "primarily." It also consists of organic plant matter that never underwent the process of biodegradation. In other words, coal is essentially a combination of dead vegetation and carbon.

The chemical process is, of course, much more complex than we've made it out to be here. You only, however, need to know the gist of it to understand why diamonds are not descended from coal.

How Are Diamonds Formed?

As we suggested before, diamonds form underground at high pressures and high temperatures, which likens them to coal in a way. Despite this small similarity in origin, however, diamonds are arguably nothing like coal.

First and foremost, coal forms much closer to the earth's surface than diamonds. This makes sense if you consider the fact that coal partly consists of plant matter, which comes from our planet's surface.

Further still, diamonds are pure phases or polymorphs of carbon. They consist purely of carbon minerals that were subjected to high temperatures and pressures. Since coal is a combination of plant matter and carbon, it cannot be considered a pure phase.

The Takeaway

So, what's the overall takeaway here? Does the fact that many of us don't know how diamonds are formed even matter? If we're being honest, not really.

Even so, debunking a myth is always fun, and the same is true of knowing exactly what's on your finger. The latter is certainly true if you paid for that diamond out of your own pocket.

So go forth and tell everyone you know that, as it turns out, a diamond is not a chunk of coal that did well under pressure. Your friends probably won't think you're much fun at parties, but they won't ever be able to tell you that you don't know your stuff about diamonds.

Have a question? We can help!

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