The simple answer is - yes.
There is such a thing as a black diamond.
The question is: is it 100% natural or treated?
A lot of black diamonds are actually treated to make the black color uniform throughout the crystal.100% black and natural diamonds, especially in big sizes, are not common.
It is also worthwhile to point out that the vast majority of black diamond Mêlées are treated.
In a case of black diamonds compared to other diamonds (colorless or naturally colored), the implication of treatments being more common is viewed in the industry a little bit the same as the heat treatments for sapphires and rubies.
With the majority of them being treated, you have to expect to pay a premium for a 100% natural one.
Black diamonds, also known as Carbonado, have long been a puzzle for Geologists.
There has been a controversy about the origin and the distribution of naturally occurring black diamonds in the world today.
A comparison of the characteristics of black diamonds as against conventional diamonds can be very informative and exciting.
Characteristics of black diamonds can be summarized as follows:
1- Black diamonds are porous, and appear to be composed of millions of minute diamond crystals, stuck together.
2- The porous material contains trapped gas bubbles, which appear to be the result of gases present when the diamonds were formed.
3- Black diamonds are tough and challenging to cut and polish.
4- The extreme hardness of black diamonds is due to a lack of crystal planes along which cleavage can occur.
5 - Black diamonds are more suitable for industrial uses such as grinding and drilling and less suitable for ornamental purposes.
6- Black diamonds are always found in alluvial deposits and never found in Kimberlite pipes, a possible indication that they did not originate deep inside the earth's crust as conventional diamonds.
Comparison of characteristics of conventional diamonds and black diamonds
Exist usually as single large crystals, formed by the build-up of giant molecules.
Non-porous, and have a classic crystal structure.No gases are present inside the crystals.
No gases are present inside the crystals.
Formed deep inside theearth's mantle under high pressure and temperature conditions.
Found in Lamproite and Kimberlite pipes, and alluvial deposits.
They are the hardest substances on earth.
There are cleavage planes in the crystal along which the diamond could be cleaved.
They are more suitable for ornamental purposes.
They are found in many parts of the world, like South Africa, Brazil, Canada, Australia, Russia, and India.
Polycrystalline, made up of large numbers of minute crystals stuck together.
They are porous in nature, similar to pumice formed from the lava.
Gases like nitrogen and hydrogen are found inside the porous material.
They are not formed deep inside the earth.
Found only in alluvial deposits.
Challenging to cut and polish.
No cleavage planes in the diamond and the extreme hardness is attributed to this.
They are more suitable for industrial purposes, such as grinding and drilling.
They are found only in Brazil and the Central African Republic.
Extra-terrestrial origin of black diamonds?
Two scientists from Florida International University, Jozsef Garai and Stephen Haggerty have proposed in a paper published in the Astrophysical Journal of December 20th, 2006, that black diamonds found in the world today are of extra-terrestrial origin.
The evidence they have given for such a view is:
1) Black diamonds are never found in Lamproite or Kimberlite pipes. They are always found in alluvial deposits only. Therefore black diamonds did not originate deep inside the earth's mantle like conventional diamonds.
2) The presence of traces of nitrogen and hydrogen gases in Carbonado indicates their ET origin. The presence of hydrogen indicates an origin in hydrogen-rich interstellar space.
3) Black diamonds are found only in two countries in the world today, Brazil and the Central African Republic, which were near one another before the continental drift, billions of years ago.
Carbonados were formed in stellar supernova explosions, and some of them were as large as asteroids, a kilometer or more in diameter.
One such Carbonado asteroid impacted the earth's surface in the region of Brazil and Central Africa, billions of years ago before the continental drift started.