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WHAT A DIAMOND MEANS
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Dictionary of
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Diamonds are crystalline carbon and the hardest known substance. This photo shows diamonds from the Argyle Mine in northern Western Australia. Photo courtesy of Argyle Diamond Mine.
Diamonds are brought to the surface from the mantle in a rare type of magma called kimberlite and erupted at a rare type of volcanic vent called a diatreme or pipe. Kimberlite is a gas-rich, potassic ultramafic igneous rock that contains the minerals olivine, phlogopite, diopside, serpentine, calcite, and minor amounts of apatite, magnetite, chromite, garnet, diamond, and other upper mantle minerals. Upper mantle xenoliths are found in some kimberlite and provide clues to the magma's origin. The source depth for kimberlite magmas is estimated at 200 km, more than twice as deep as the source region for most magmas. At a depth of 200 km the pressure is 60,000 times greater than the surface and the temperature is about 1500 C. Kimberlite magmas are rich in carbon dioxide and water which brings the magma quickly and violently to the surface. Most kimberlites occur as multiple intrusive events. Kimberlite was named for the rock associated with diamonds in Kimberley, South Africa.
Kimberlite magmas form "pipes" as they erupt. A tuff cone is at the surface and formed by base-surge deposits. In the subsurface, a funnel-shaped body narrows to a depth of hundreds of meters. The pipe (also called a diatreme) is filled with kimberlite, with or without diamonds (only 1 in 5 of the pipes at Kimberley contain diamonds). Simplified from Hawthorne (1975).
Just how many diamonds are needed to make a pipe economical? Some South African mines operate at 25 carats of diamond per 100 cubic meters of rock or about 2 grams of diamonds per 100 tons of rock. Because diamond has a specific gravity of 3.5 grams per cubic centimeter, 1 cubic centimeter of diamond weighs 16 carats. Picture a giant 100-ton ore truck full of kimberlite - that truck contains only half of a cubic centimeter of diamonds! Only about 35% of those diamonds are gem quality.
Macles diamonds from the Argyle pipe, Western Australia. Photo courtesy Grand Boxer.
Most diamonds are used in drill bits and diamond tools. A small number are used for glass cutters and surgical instruments. Only the finest are used as gems.
Australia is currently the world's largest producer of diamonds. Most of these diamonds are low quality and used for industrial purposes. Most of the diamonds are from the Argyle diamond pipe in northern Western Australia. The pipe at Argyle is made of lamproite, not kimberlite. The mine produced 27.8 million carats (1 ct = 200 mg; 5 carats = 1 gram) of low grade diamonds in 1993-1994. Because of the high rate of production at Argyle, mining operations will end within the next few years.
The mines at Kimberley, South Africa have produced a total of more than 200 million carats since the 1870s. About half of South Africa's diamonds are gem quality.
It should come as no surprise that our culture was not the first to be lured by the hypnotic spell the diamond casts. Consider the ancient Greeks and Romans who believed diamonds were tears of the Gods and splinters from falling stars. Then, there were the Hindus, who attributed so much power to these precious stones they went so far as to place diamonds in the eyes of some of their statues. The very word 'diamond' comes from the Greek term adamas meaning unconquerable or invincible.
Not only was it believed that diamonds could bring luck and success, but also that they could counter the effects of astrological events. There were many that wore diamonds as charms believing in their ability to heighten sexual prowess and attract others. Plato even wrote about diamonds as living beings, embodying celestial spirits.
Through the centuries, rings have perpetuated the talismanic role of the diamond. In the Middle Ages and Renaissance period, every ring that was set with a precious stone was considered not so much a piece of jewelery than an amulet that conveyed magical powers like fearlessness and invincibility upon the wearer. This myth laid the groundwork for monarchs to begin wearing diamonds as symbols of power.
Today, diamonds continue to hold a deep fascination as the world’s ultimate symbol of love. The diamond’s rarity and natural beauty have contributed to making it such an extraordinary and magical gift. Furthermore, the timeless history of each diamond makes it the most meaningful and powerful way to symbolize eternal love.
What many people don’t know about diamonds is that they were formed under immense heat and pressure hundreds of miles below sea level. Diamonds were formed billions of years ago under intense heat and pressure when diamond-bearing ore was brought to the surface through volcanic eruption. After the magma cooled, it solidified into blue ground, or kimberlite, where precious rough diamonds are still found today. Rated 10 on the Mohs scale of hardness, diamonds are the hardest substances on earth, but their appeal goes far beyond durability
Adding to the mystery and aura of what make diamonds so sought-after, approximately 250 tons of ore must be mined and processed in order to produce a single, one-carat, polished, gem-quality diamond.
It was over 4,000 years ago that the first diamonds were mined in India. Modern mining as we know it today began in South Africa in the late 19th century. Today, the top seven diamond-producing countries, accounting for 80 percent of the world’s rough diamond supply, are Botswana, Russia, South Africa, Angola, Namibia, Australia and Zaire.
There are two speculated reasons. The rings were actually worn on the thumb in the 17th century, but the 4th finger was used during the ceremony. Some feel that during a Christian wedding, the priest arrives at the 4th finger after touching three fingers on the left hand "In the Name of the Father...Son...and Holy Ghost...". Others believe the Egyptian myth that the ring finger follows the "vena amoris" or vein of love...which supposedly runs directly to the heart.
The following article is from BBC News
Twinkling in the sky is a diamond
star of 10 billion trillion trillion carats, astronomers have discovered.
The cosmic diamond is a chunk of crystallised carbon, 4,000 km across,
some 50 light-years from the Earth in the constellation Centaurus.
It's the compressed heart of an old star that was once bright like our Sun but has since faded and shrunk.
Astronomers have decided to call the star "Lucy" after the Beatles song, Lucy in the Sky with Diamonds.
Twinkle twinkle
"You would need a jeweller's loupe the size of the Sun to grade this diamond," says astronomer Travis Metcalfe, of the Harvard-Smithsonian Center for Astrophysics, who led the team of researchers that discovered it.
The diamond star completely outclasses the largest diamond on Earth, the 530-carat Star of Africa which resides in the British Crown Jewels.
The huge cosmic diamond - technically known as BPM 37093 - is actually a crystallised white dwarf. A white dwarf is the hot core of a star, left over after the star uses up its nuclear fuel and dies. It is made mostly of carbon.
For more than four decades, astronomers have thought that the interiors of white dwarfs crystallised, but obtaining direct evidence became possible only recently.
The white dwarf is not only radiant but also rings like a gigantic gong, undergoing constant pulsations.
"By measuring those pulsations, we were able to study the hidden interior of the white dwarf, just like seismograph measurements of earthquakes allow geologists to study the interior of the Earth.
"We figured out that the carbon interior of this white dwarf has solidified to form the galaxy's largest diamond," says Metcalfe.
Astronomers expect our Sun will become a white dwarf when it dies 5 billion years from now. Some two billion years after that, the Sun's ember core will crystallise as well, leaving a giant diamond in the centre of the solar system.
"Our Sun will become a diamond that truly is forever," says Metcalfe.
Chemistry: C, Elemental Carbon
Class: Native Elements
Subclass: Non-metallics
Group: Carbon
Uses: as a gemstone and abrasive.
Diamond is the ultimate gemstone, having few weaknesses and many strengths. It is well known that Diamond is the hardest substance found in nature, but few people realize that Diamond is four times harder than the next hardest natural mineral, corundum (sapphire and ruby). But even as hard as it is, it is not impervious. Diamond has four directions of cleavage, meaning that if it receives a sharp blow in one of these directions it will cleave, or split. A skilled diamond setter and/or jeweler will prevent any of these directions from being in a position to be struck while mounted in a jewelery piece. As a gemstone, Diamond's single flaw (perfect cleavage) is far outdistanced by the sum of its positive qualities. It has a broad color range, high refraction, high dispersion or fire, very low reactivity to chemicals, rarity, and of course, extreme hardness and durability. Diamond is the April Birthstone.
In terms of its physical properties, diamond is the ultimate mineral in several ways:
Diamond is a polymorph of the element carbon. Graphite is another polymorph. The two share the same chemistry, carbon, but have very different structures and properties. Diamond is hard, Graphite is soft (the "lead" of a pencil). Diamond is an excellent electrical insulator, Graphite is a good conductor of electricity. Diamond is the ultimate abrasive, Graphite is a very good lubricant. Diamond is transparent, Graphite is opaque. Diamond crystallizes in the Isometric system and graphite crystallizes in the hexagonal system. Somewhat of a surprise is that at surface temperatures and pressures, Graphite is the stable form of carbon. In fact, all diamonds at or near the surface of the Earth are currently undergoing a transformation into Graphite. This reaction, fortunately, is extremely slow.
PHYSICAL CHARACTERISTICS:
| A diamond is found naturally in the rough form. It looks much like a crystal and lacks any real lustre. The true brilliance and fire of the stone is only unlocked after a number of processes described below. These processes can all be performed by different specialists |  |
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Marking: The first step in diamond cutting is the examination of the stone in the rough form. Each stone is totally unique and so must be studied in detail in order to determine the finished shape that will retain as much weight as possible. The stone is then marked with India ink to indicate how it must be divided. |
| Cleaving: To cut a rough stone, it is first set in a 'dop' or holder using quick drying cement. Then, using another diamond, a small groove is made along the division line. A square-edged knife is then inserted into the groove and tapped sharply with a mallet. It is this action that determines the diamond's future as if the division line has not been placed properly, or followed accurately, the diamond can shatter. Cleaving is always done parallel with the grain of the diamond. |
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Sawing: Sawing is the process by which a diamond is cut against the grain. Before a diamond is sawn, it is mounted again in a 'dop' or holder. It is then lowered slowly on to a vertically positioned saw spinning at high speed (up to 15,000rpm). The blade is made of phosphor bronze and is coated with diamond powder mixed with oil. The sawing of a large stone can sometimes take weeks. |
| Bruting: During this stage of the process, the diamond's girdle is formed. This is also known as girdling or rounding. The girdle is the band which is formed around the thickest part of the stone. To form the girdle, the stone is again set in a 'dop' which is in turn fixed on to the centre of a lathe which spins at high speed. Using another diamond set in a long 'bruting stick', the corners of the rough stone are gradually rounded off until the spinning diamond is perfectly round at its thickest part. |
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Blocking or Cross Work: This is the final stage in the making of a polished diamond. It is during this time that the diamond's facets are polished onto the stone. This is done using a horizontally mounted circular cast iron disc known as a scaife. The scaife is of course impregnated with oil and diamond dust. The diamond to be polished is set in an adjustable dop at a certain angle and lowered onto the plate. The angle of the diamond must be changed for each facet. On a brilliant cut diamond there are usually 57 facets. |
The above
images and information are courtesy of the HRD
Antwerp World Diamond Center |
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In 1994, Pauline Willemse cut the world's smallest diamond. It was 50 times smaller than the head of a ballpoint pen.
The largest diamond ever found was the Cullinan at 3,106 carats. Known also as the Star of Africa, it adorns the scepter of King Edward VII of England. The Tower of London is its current home.
Most expensive diamond: $16,548,750. It was bought in 1997 and was 100 carats.
The easiest way to spot the difference between a diamond and cubic zirconia is to weigh it. Cubic zirconia weigh 55% more than diamonds.
Diamonds can be completely consumed by fire at temperatures ranging from 1,400° to 1,607° F., depending on the hardness of the gem.
The first recorded diamond engagement ring was given to Mary of Burgundy from Archduke Maximillian of Austria in 1477 as a betrothal gift.
On May 13, 1888, using a pen encrusted with diamonds and emeralds, the Princess Imperial Regent Dona Isabel signed the decree ending slavery in Brazil. With a single stroke, she liberated 1,500,000 men, women and children, and brought freedom to the last slave-holding country in the western hemisphere.
It is believed that a diamond: endows the wearer with courage and fortitude; brings victory and good fortune; wards off evil; protects against the plague; promotes constancy in a marriage.
THE APRIL BIRTH STONE
Diamond Facts and Curiosities
The first distinct and undoubted reference to diamonds occurs in Roman literature of the 1st century AD. The diamonds known to the Romans undoubtedly came from India.
All the rough gem quality diamonds found in the world in one year could be carried by a 2.5 ton truck.
Diamonds are 140 times harder than rubies or sapphires. And 180 times harder than emeralds.
During the Roman era it was believed that swallowing a diamond would counteract poison.
"The Hindus believed that a flawed diamond, or one containing specks or spots, was so unlucky that it could even deprive Indra of his highest heaven. The original shape of the stone was also considered of great importance, more especially in early times, when but few, if any, diamonds, were cut. A triangular stone was said to cause quarrels, a square diamond inspired the wearer with vague terrors; a five-cornered stone had the worst effect of all, for it brought death; only the six-cornered diamond was productive of good."
Diamond is attracted to grease, as funny as it may sound this principal is utilized to aid in sorting at the mines. Because of this characteristic it is recommended that you wash diamond frequently to remove cooking grease, body oils and the like. This will keep it shinning in all of its glory. It is forever . . .
Zsa Zsa Gabor said she never hated any man enough to give him back the diamonds they gave her.
