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Ah! The wonders that await us deep within the Earth’s upper mantle. Among these, none shine as bright as carbon-rich diamonds. These precious gemstones form under great pressure, usually somewhere near 100 miles below the surface.
Kimberlite volcanism coupled with continental breakup ultimately pushes these precious gemstones to the surface. If you ask a layman, they may be tempted to determine the value of a diamond simply by how shiny and eye-pleasing it is. Gemologists know better than to merely judge a stone by its ‘cover.’
They are essentially hunting for so-called imperfections or inclusions found deep within the diamond, much like a mosquito stuck in amber. Sometimes, this enables them to discover unexpected results that alter their scientific journey in a novel direction.
In this article, we will discuss diamond inclusions in light of their importance and scientific progression to date.
What We Know So Far
Do you remember the notable mosquito of Jurassic Park that carried with it the DNA of extinct dinosaurs? A diamond’s inclusions or imperfections are much like that mosquito. They hold valuable information about a particular stone’s origins and formation.
In a nutshell, studying these inclusions can offer us a glimpse into the diamond’s life. That imparts a lot of meaning to the term ‘imperfection’ which is often viewed as a characteristic flaw.
Now, there may be external or internal inclusions. Examples of imperfection in a diamond include cloud, feather, indented natural, abrasions, and burn marks, among others.
Since these inclusions affect how light reflects from the stone, some may provide better results than others. Moreover, Leibish states that certain diamonds have such an intense color that their inclusions may blend with it.
Another scenario can be inclusions that are too dense or large. These will have a negative impact on the stone’s light transmission properties, thereby giving the stone a hazy appearance. Similar to birthmarks, diamond inclusions affect one of the important 4Cs of the stone, namely, clarity.
For instance - an internally flawless (IF) grade stone would show only minor blemishes even under 10x magnification. Similarly, the other end of the scale includes the grades I1, I2, or I3 suggesting that inclusions are obvious under 10x magnification. Such diamonds’ brilliance and transparency may be compromised.
What We’re Gradually Discovering: Groundbreaking Findings
The best part about diamond inclusions or imperfections is the brewing sense of ambiguity. We do know a lot, but there is this awareness among scientists that there’s always more to discover. Likewise, two recent disruptive findings have been made.
Light Grey-Blue Color Attributed to Cloud Inclusions
The scientists at the Gemological Institute of America (GIA) recently received a 2.20-carat diamond for grading. It was interesting to note that the stone had a fascinating light greyish-blue color.
At first, all common sources that impart a diamond its characteristic blue color were ruled out. This included hydrogen-related absorption, boron, and natural/artificial irradiation. This diamond was truly unique with no boron impurities or GRI-related color centers.
Another rare thing that GIA scientists observed was the stone’s UV absorption. It was found to be similar to that of a type Ib yellow diamond. After much study, it was discovered that the diamond’s milky cloud inclusions were responsible for imparting the light blue color.
This gemstone was truly one of its kind because the GIA stated that cloud inclusions generally render the diamond brown, white, grey, or black. When it comes to the stone in question, the cloud inclusions led to Rayleigh light scattering.
It is the same phenomenon that gives the sky its hallmark blue color of the day. Hence, the final result was not the expected yellow but the unexpected light greyish blue.
Sulfide Inclusions Reveal Continental Development and Movement
Previously, we mentioned how diamond imperfections hold hidden secrets of the stone’s life. In a recent shocking discovery, scientists believe they have found the answer to the famous continental drift. It all happened due to dating the origins of minuscule sulfide and silicate inclusions.
Antique and super-deep diamonds were chosen for analysis from the mines of Western Africa and Brazil. What researchers discovered is that super-deep diamonds were forming beneath Gondwana’s surface when it covered the South Pole. That would range between 650-450 million years ago.
The host rocks gained buoyancy due to diamond formation, thereby transporting sub-mantle material as well as the stones. This material settled at the base of the root of Gondwana, gradually growing the supercontinent.
Over hundreds of millions of years, this supercontinent started breaking off to give way to oceans like the Atlantic. Closely, the super-deep diamonds also followed, bringing the trapped sulfide inclusions with them to the Earth’s surface.
Who would have thought that nature’s most well-kept secret would traverse the span of time and space in such a great manner? Besides revealing secrets, inclusions also affect a diamond’s price. Naturally, ones that score high in terms of clarity will come attached with a higher price tag.
In the final analysis, the international diamond market was spurred into motion by the 2022 Ukraine-Russia conflict. It is currently maintaining a CAGR of 4.5%, expected to become $155.5 billion by 2032.
Challenges will also abound due to macroeconomic instability, pressures from the lab-grown market, and Russian sanctions. Fluctuations in price are expected this year, hence, close monitoring of the market is advised. 2024 may not be the year of standardization and generalizations.