What do loose diamonds have in common with a pile of coal? More than you think; in fact, in geological terms, loose diamonds are nothing more than glorified chunks of coal. The difference are:
– the arrangement of carbon atoms
– how each material is formed
Even when it comes to diamond formation, the difference between the processes is one of degree rather than mechanics. Here is some interesting information for potential buyers of certified wholesale diamonds.
carbon is carbon
Some may remember an episode of the old “Superman” TV series from the 1950s in which Clark Kent created a diamond by compacting a lump of coal in his fist. While it is doubtful that even the “Man of Steel” could wield geological forces as supernatural as those taking place deep within the earth, the enlightened concept was essentially correct: those loose diamonds that eventually end up with the diamond dealers who sold to jewelers are made from carbon that has been subjected to extremely high pressures of 60 kilobars (for comparison, that’s 60,000 times normal air pressure at sea level) and temperatures of over 2300 degrees Fahrenheit (structural steel! melts at about 1520° F)!
The pressure and heat needed to create diamonds is found only in the Earth’s lithosphere, where the crust meets the upper mantle, between 90 and 240 miles below the surface. Diamonds can also be formed when a meteorite hits the earth’s surface, creating similar conditions, or are transported within the meteorite (some diamonds come from outer space!).
Coal, on the other hand, forms from the decaying remains of ancient plant matter that has also been compressed by geological forces, but much closer to the surface. In chemical terms, the carbon atoms that make up carbon molecules are arranged in a flat hexagonal pattern, which makes them much more brittle. However, in diamond, they are arranged in a tetrahedral or box-shaped structure. This is what explains the hardness of loose diamonds.
Can one become the other?
Eventually, if a coal deposit is sunk low enough into the earth and subjected to high pressure and temperature, it can turn into diamond. Theoretically, diamond could also be converted to carbon, if kept free from chemical reactions that color gems and stabilize the surface, and then put under vacuum. However, this is unlikely outside of controlled laboratory conditions.
Loose diamonds are made, not born
What we call loose diamonds do not occur naturally. Once the diamond is mined, it is graded into “industrial grade” and “gem grade.” The last category is the one that is subject to diamond appraisal by diamond dealers.
The rough diamond is cut into loose diamonds, then craftsmen carefully carve and shape them into shapes suitable for decorative jewelry. This stage can have a huge impact on the value of loose diamonds as determined by a diamond appraisal, and must be done with painstaking care and uncommon skill.
Wholesale certified diamonds must also be tested and graded by a professional gemology lab. It is here that the stones are evaluated for carat, color and clarity. Together with the results of the diamond appraisal evaluating the cut, they provide the basis for valuation.
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