Miranti

Black Diamonds Part II: The Gem from Outer Space

The origin of this extremely rare gem remains a mystery.  While normal diamonds are created by tremendous earth pressure and can be found in several locations around the planet where these high-pressure conditions occurred, not a single black diamond has ever been discovered in a traditional diamond mine.  They are mostly discovered in riverbeds, and so far only in two countries and two different continents, Brazil (South America) and in Central African Republic (Africa).

Professor Stephen Haggerty and Jozsef Garai of Florida International University analyzed the hydrogen content in black diamond samples using infrared-detection instruments and found that the quantity indicated that the mineral formed in a supernova explosion. "The presence of hydrogen in the carbonado diamonds indicates an origin in hydrogen-rich interstellar space."

The most prominent theory is that black diamonds traveled on an asteroid that collided with earth.  What is interesting is that the two countries that yield black diamonds were once next to each other, 350 million years ago, when Africa and South America were one supercontinent, Pangea.

It is believed that a large asteroid struck the area of Pangea where the continents would eventually split, and dispersed the black diamonds on impact.  So far, no other explanation makes sense.

Black diamonds are not widely known and not that many jewelers are interested in them enough to create a marketing campaign that would drive the price up. If you are looking for a nice contrast for white diamond jewelry, black diamond is a great match because of its price, hardness and beauty.

This is a picture of a ring of mine that was designed by a jeweler who intended to use all white diamonds but I redesigned it, substituting two rows of black diamonds on each petal. This drove the price down approximately 20-30% overall.

The loose black diamond price in the market was significantly lower than white diamonds at this time because of the rule of supply and demand.  Carat for carat, black diamonds are a quarter the price of medium quality white diamonds.

Some company who might want to monopolize the black diamond market could use the slogan “Black Diamonds—truly out of this world.”

Reference

http://www.pbs.org/wgbh/nova/diamond/sky.html

Black Diamonds

I have a few pieces of jewelry that contain black diamonds. Every time I wear them, I either get compliments or questions. What is black diamond?

Black diamond, or "Carbonado" named by the Brazilians who discovered them, is a natural polycrystalline diamond. Black diamonds, even though they are between 2.6 - 3.8 billion years old, were discovered by mankind around 1843 in Bahia, NE Brazil. They are normally found only in Brazil and in Central African Republic (more on this later in the next session.)

Mostly used as industrial diamonds for drilling and polishing, black diamonds are as hard as regular diamonds (given a value of 10 in the Mohs hardness scale), but are filled with pores, which absorb light rather than reflect it.  They are much more brittle than normal diamonds, so cutting and polishing them into jewels is much more difficult.

It took a Florentine jeweler, Fawaz Gruosi, to turn black diamonds into the exotic jewelry that is now available.  In 1996 Gruosi, in his Swiss jewelry firm de Grisogono, began designing and selling black diamond jewelry.  Several large black diamonds were cut before Gruosi, but they never achieved the same popularity.

Black diamonds represent a challenge to jewelers, as 30% more of the material is lost in cutting and polishing than with regular diamonds, primarily due to the greater brittleness of this unique stone. The largest uncut black diamond was discovered in 1895 and weighed 3072 carats, and was as the size of a large pear. It is not known what happened to this stone.

The largest cut black diamond is 312 carats, and is called Spirit of de Grisogono, (created by Mr. Gruosi) and was cut from 587 carats.

The second largest is the Black Star of Africa, at 202 carats, but its owner and location is currently not known. It was on exhibit in Tokyo in 1971 and was valued at 1.2 million dollars U.S.

The third largest is the Table of Islam, a 160-carat emerald cut. It was last reported for sale in January 1992.

The fourth largest, and most famous, is the Black Orlov, also known as the "Eye of Brahma" at 67.5 carats, cushion cut. It is currently owned by J. Dennis Petimezas, president of Watchmaker’s Diamonds and Jewelry. The diamond was worn by Felicity Huffman to accept the Oscar for the best actress in 2006.

In earlier times, the Black Diamond was seen as the “stone of reconciliation”. Wave a Black Diamond in the face of the spouse with whom you’ve just had a fight and all will be well again. If you can’t afford a regular diamond, which is guaranteed to work, give it a try.

To be continued