With carbon atoms present and conditions perfect, diamonds are formed when the carbon atoms are crystallized under tremendous pressure and heat.  This occurs deep within the Earth in its semi-molten upper mantle beneath the massive continental plates nearly 100 miles or more below the surface.  Once formed, the crystallized carbon is transported to the surface in kimberlitic or lamproitic magmas through the chimneys of fiery volcanoes as they erupt.  When these magmas cool, they become the "host" rock of the diamonds, kimberlite and lamproite.

It is interesting to note that the crystallization process for any group of carbon atoms is dependent upon a number of variable factors.  For that reason, there is no guarantee that they will crystallize into a diamond or, if they do crystallize, that they will reach the surface as a diamond, . . . even though they may start out under perfect conditions.  If they are swirled deeper into the magma, diamonds revert to carbon atoms.  If cooled slowly as they rise, they will convert to graphite.  If they come into contact with oxygen while still hot, they vaporize to carbon dioxide.  Only when they rise and cool rapidly between the mantle and the surface do they survive as diamonds.

After the molten substance in the volcanic pipe has cooled and the volcano begins to erode, the diamond-baring material, kimberlite and lamproite, in the pipe is also exposed to weathering and glacial action. As the erosion process continues over millions of years, some diamonds are released to be scattered in all directions.  Those washed into rivers can collect into what are referred to as alluvial deposits while others may be carried hundreds of miles away.  Many diamonds are even washed out to sea where, as a result of wave and tidal action, they have rolled and tumbled onto beaches.  These are called beach deposits. Mother nature was very generous when used these methods of sharing her precious gems with us because some of the diamonds deposited both ways can, very literally, be picked up off the ground.

Alluvial deposits yielded the first diamonds that were mined over 2,000 years ago in the Golconda region of India, between the Godavari and Krislina Rivers.  The existence of these diamond mines was known to both the Ancient Greeks and the Romans.  The writings of both Aristotle and Pliny referenced a distant fabled "valley of diamonds".  The Indian diamond mines are also believed to be basis for a reference in the story of Sinbad the Sailor in the book Arabian Nights. In the story, eagles were used to carry diamond-encrusted pieces of meat from a snake filled valley up to their nests where they could be collected.  Whether myth or fact, stories of diamonds have fired both imaginations and dreams since first discovered. 

Throughout the years, we have collected many very interesting and unbelievable stories about diamonds and diamond mines that we intend to share in the future.  So, come back and visit us often.

Certainly not a myth though, the Indian diamond mines have produced some large and very famous diamonds.  Among these are the 109 carat Koh-i-noor (British Crown Jewels), the 190 carat Orlov (Russian Imperial Scepter) and the magnificent 69 carat dark blue Hope Diamond of Louis XIV, one of the most famous diamonds, currently in the Smithsonian Museum of Natural History.

The Golconda region diamond mines became the primary source for diamonds until Portuguese gold washers discovered alluvial deposits in Brazil in 1725 in the Tejuca region of Minas Gerais, 300 miles north of Rio de Janeiro.  With the supply diminishing in India, Brazil became the world's principal producer until the 1870s, nearly 150 years.  Neither of these locations are considered major diamond production centers today with only about 1% of world production combined.

When a long extinct volcano has been reduced to little more than gently rolling landscape, it can hide its volcanic kimberlite or lamproite pipe and stored treasure of diamonds for many more millions of years.  However, once discovered, the sight hums with activity and roars with the sound of heavy equipment dedicated to unearthing the treasure.  This part of the story of diamonds began in South Africa.

The South African diamond rush of the 1870s and 1880s is attributed to an 1866 discovery by a young farm boy.  The boy who lived on the De Kalk farm, approximately 30 miles northwest of Hopetown, was walking near the banks of the Orange River when he found a large diamond.  The 21 carat rough was later cut to 10.73 carats. This beautiful yellow diamond is now, appropriately enough, known as the "Eureka".

This South African discovery prompted a search for more diamonds and created a hope for finding their source. Three years after finding the Eureka, the much larger and more famous 83.5 carat 'Star of South Africa' was discovered.  The following year another large 50 carat diamond was located still in its host rock. This proved to be the first kimberlite pipe ever discovered and recognized as the source of diamonds.  This pipe is the present day site of the famous Jagersfontein Mine in the Orange Free State.  When geologists finally discovered that diamonds were transported to the surface through volcanic pipes, the rush to discover and recover became a feverish reality.  After the first discoveries of kimberlite pipes, several more soon followed at Bultfontein, Dutoitspan, De Beers, Koffiefontein and Kimberly or the 'Big Hole'.  The recovery process roars today as strong as ever in South Africa where most of the world's large diamonds continue to be found.

With the discovery of diamonds in South Africa, the search quickly spread to its neighbor, Namibia, where deposits were discovered in 1908. Subsequently, deposits were found in Angola, Ghana, Sierra Leone, Tanzania, Congo, Guinea, Central African Republic, Ivory Coast and Liberia.

Diamond deposits were discovered in Russia in 1953.  The story is told that these diamond deposits were discovered when a geologist saw a fox with a blue belly emerging from a hole.  The blue coloring had come from "Blue Ground" which is associated with diamond-bearing deposits of kimberlite.

Botswana was next when deposits were discovered in 1967.  These mines are noted for producing some of the finest quality diamonds.  In 1979, diamond deposits were discovered in Australia.  The Argyle Mine in Australia has become renowned for its high value pink diamonds and is also credited with developing a market for "champagne" colored diamonds.  This mine is currently the world's largest producing single mine.

Kimberlite was discovered in Canadian in 1946. In 1991, a diamond rush began there when "significant" diamond-bearing deposits were discovered in the Lac de Gras region of the Northwest Territories.

For those of you who are reading The Story of Diamonds in the United States and asking, "What about us?" . . . well, the answer is, "Yes, diamonds have even been found in the United States."  While diamond mining in our country has been negligible . . . they are here.

The first diamonds found in the United States were discovered in alluvial deposits in the 1840's.  Since that time, they have been found in other similar widely separated diamond deposits.  The first diamond discovered in the United States in one of its host rocks, lamproite, was found at Prairie Creek, near Murfreesboro, Arkansas.  As in South Africa, this discovery is attributed to an initial find on a farm.  The farmer gathered several of the small luminous stones that were simply lying on the ground around the farm.  Remember, we told you that diamonds in alluvial deposits could be picked up off the ground.  Anyway, . . . he sent the stones to an expert for identification and . . we know you've guessed the rest . . . DIAMONDS!

Eventually, with the subsequent discovery of a diamond-baring volcanic pipe, a mining company was established at the site which had become known as "Crater of Diamonds".  Because the site is very large and commercial mining is quite expensive, the company only operated until 1919, when closed because it was not profitable.  Later, the State of Arkansas designated the area as Crater of Diamonds State Park.  So, if reading our story has given you the urge to go unearth your own diamond, for a small fee . . . you can go on your own very real treasure hunt.  Who knows what you might find?  In 1955, a woman turned over a clod of dirt and discovered a flawless and colorless diamond weighing 15.33 carats.  She had it cut into an 8.27 carat marquise shape which is now known as the "Star of Arkansas".  Another find at the Crater of Diamonds, a 4.23 fancy yellow diamond, was worn by Hillary Rodham Clinton to some of the presidential inaugural events in 1993.  And, a certainty . . . there are other diamonds still waiting to be found.

Mining diamonds from pipes certainly requires more effort than just bending over or some of the superficial digging you might do at Crater of Diamonds.  Mining the kimberlite pipes, which first occurred in South Africa, is also much different than mining the secondary alluvial deposits.  The effort to recover diamonds from the volcanic pipe can take miners nearly 4,000 feet straight down.  Mining the pipes usually involves sinking vertical shafts in the rock adjacent to the pipe, then tunnels are dug from the shaft to the pipe.  When the pipe is reached, miners blast tremendous quantities of diamondiferous (diamond-baring) rock, load it into tunnel trucks and move it to the shaft.  The rock is transported up the shaft and on to a processing plant.

At the processing plant, the rock is crushed down to gravel size and run along a conveyor belt for automatic sorting or the gravel is run over a grease table, a somewhat less automated system.  In either event the goal is to separate rough diamonds from the rock.
 

A fter being separated from their native rock, diamonds are gathered for sorting.  As can be seen here, they are found in a wide variety of sizes and colors . . . from black to bright fancy colors.

A fter having been gathered for sorting, rough diamonds are further separated based on size and color.

T hese diamonds have been sorted and are being readied for the cutter.  As you can see here, they don't have the magnificent sparkle that will be released after being cut.