The Development of Civilization - Volume 6 Part 2: It’s Elementary - Diamonds

(From “An Introduction to Faunapology” by Octavius Bear PhD.)

Diamonds are renowned for their extraordinary physical qualities, caused by strong bonding between their atoms. They have the greatest hardness and thermal conductivity of any material. The word comes from the ancient Greek - adámas “indestructible”.

GIA, The non-profit Gemological Institute of America categorizes diamonds by color, cut, clarity and carat (weight)

Color: In addition to the clear, colorless gems that make up most jewelry, some impurities may color diamonds blue, brown, yellow, green, purple, pink, orange and red. The famous Hope Diamond is a deep blue. Diamonds also can disperse light of different colors.

Cuts and shapes: Cut refers to the symmetry, polish and proportioning of a diamond. The cut of a diamond greatly affects a diamond’s brilliance. The finer the cut, the greater the brilliance and fire of the diamond. Shapes include round, princess, pear, marquise, oval, heart, emerald, baguettes and cushion.

Clarity is a metric that grades the visual appearance of each diamond. The less inclusions and blemishes, the better the clarity grade.

Carat (ct.) refers to the unique unit of weight measurement used exclusively to weigh gems and diamonds. It is not necessarily indicative of size. The Hope diamond has a weight of 45.52 carats.

The hardness of diamonds also makes them an ideal material for industrial use in cutting and grinding tools. As the hardest known naturally occurring material, diamonds can be used to polish, cut, or wear away any material, including other diamonds. Common industrial applications of this property include diamond-tipped drill bits and saws, and the use of diamond powder as an abrasive. Less expensive industrial-grade diamonds, with more flaws and poorer color than gems, are used for such purposes.

The market for diamonds has been dominated for decades by the DeBears group. (No relation.) Unfortunately, until recently there has also been a brisk trade in blood diamonds that we have described previously. Several other groups round out the major sources of gemstones.

Most natural diamonds are formed at high temperature and pressure at depths of 140 to 190 kilometers (87 to 118 mi) in the Earth’s mantle. Minerals containing carbon provide the source, and the growth occurs over periods from 1 billion to 3.3 billion years. Diamonds are brought close to the Earth’s surface through deep volcanic eruptions by magma.

Diamonds can also be produced synthetically in a High Pressure High Temperature (HPHT) method which approximately simulates the conditions in the Earth’s mantle. An alternative, and completely different growth technique is chemical vapor deposition (CVD).

Several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamonds in appearance and many properties. Special techniques have been developed to distinguish natural diamonds, synthetic diamonds, and diamond simulants. One characteristic leading to diamond identification is its superior thermal conductivity. Electronic thermal probes are widely used in the gemological centers to separate diamonds from their imitations.

Then, of course, there is the Chita sniff-test which unerringly succeeds in identifying the real thing.