Exploring the Gemology of Diamonds

diamond gemology - diamond engagement ringsThe diamond: It’s a gem that is much rarer than most of us could ever imagine. For decades, it’s been referred to in pop culture—and in jewelry store advertisements—as “a girl’s best friend.” It’s also the hardest natural material on earth, literally. But how much do you really know about that sparkling cut of ice that’s attached to your custom diamond engagement ring?

Here’s the thing about diamonds: Even if you were bored to death by your high school geology class, you’ll probably be surprised to learn just how fascinating the story of the diamond really is.

How Is a Diamond Formed?

We’ll be the first to admit that the science behind the geology of diamond formation is pretty complicated stuff. Thankfully, the most important details are also the most interesting.

For starters, it’s important to understand that the factors required for a diamond to be created are unusually rare. First, carbon-bearing rocks must exist at a depth of 87 and 118 miles below the surface of the earth—no more and no less.

A very specific sort of volcanic eruption brings those diamond-bearing rocks to the Earth’s surface, assuming an enormous amount of pressure has been placed upon them during the millions of years they’ve existed. Even given all that rarity, only five percent of all mined diamonds are considered to be of gem quality. The other 95 percent are used in industrial applications, mostly for industrial cutting, drilling and polishing tools. They can also be found in high-quality speakers, and even windows.

Why Do Diamonds Sparkle?

To put it simply, diamonds have a unique capacity to reflect light that’s often referred to as their “mirror effect.” Diamonds are also capable of separating light waves, and those two factors play a large role in creating what we think of as a diamond’s brilliant sparkle.

More specifically, the quality and grandeur of a diamond’s sparkle will always come down to its cut. It takes a craftsperson with an enormous amount of training and skill to properly shape and cut a diamond, which can actually have as many as 57 facets, or sides. The more precise the cut, the more brilliantly a diamond reflects light. Given the small size of most diamonds and the incredibly intricate cuts that are popular today, you can imagine how difficult and time-consuming it is to shape a diamond with expert-level precision.

How Are Raw Diamonds Cut?

Very, very carefully! Seriously, though: If you consider that diamonds are the world’s hardest natural material, you’ve got to wonder: What could possibly be used to cut and shape them? The answer, of course, is other diamonds. When they’re cut by hand, two stick-like instruments with a diamond attached at each end are used in a process known as bruiting, with one diamond cutting the other. Before that can happen, however, a cutter must “cleave” one rough diamond into two by whacking it along its weakest plane with a small steel blade. If a diamond has no plane of weakness, it will instead be sawed, either with a phosphor-bronze blade or a laser.

Are All Diamonds Flawed?

Yes, there is such a thing as a diamond with flawless clarity, but it doesn’t happen often. Professionals use jewelry loupes to search for such diamond imperfections as feathers, clouds, cavities, and knots. These are either tiny blemishes of some sort, or perhaps miniscule drops of fluid, or even bits of other minerals. Interestingly, however, these blemishes and imperfections tend to be coveted by geologists, who use them to learn otherwise hard-to-gain facts about the specific section of deep Earth from whence each diamond originates.

Will Humans Always Be Needed to Cut Diamonds?

That’s a tough question to answer. But it’s worth noting that when a rough diamond is polished by human hands, an astonishing 70 percent of the gem can be lost. You can find amazing before-and-after photos online of rough diamonds that have been polished by gemology experts, the very best of whom can visualize a diamond’s ideal polished shape inside its rough version. It’s an innate process that’s not unlike that of sculptors who claim to visualize their finished work of art inside a slab of raw stone.

Nevertheless, most diamonds bound for the high-end retail market today are cut by very advanced lasers and scanners. Computers are used in this process to determine the ideal cut, given the raw diamond’s shape. The result is a loss of only 30 to 40 percent.

If you’re looking to buy or sell wholesale diamonds, Doylestown Gold Exchange can help. Owner Greg Glemser is a graduate gemologist, with certification from the Gemological Institute of America, the country’s premier school for jewelers.

Contact us today to learn more about how we can help you complete your diamond education.

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