natural diamond

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.

Natural diamond is formed where carbon has crystallized under exposure to high pressure and temperature. the pressure must be between 45 and 60 kilobars and the temperature between 900 and 1300 °C.

These conditions occur naturally only in the lithospheric mantle, below the continental plates, and at meteorite strike sites.

In the lithospheric mantle, the proper temperature and pressure are usually found in depths of 140-190 kilometers. The correct combination of temperature and pressure is only found in the thick, ancient, and stable parts of continental plates where regions of lithosphere known as cratons exist. Presence in the cratonic lithosphere for long periods of time allows diamond crystals to grow larger.
The slightly misshapen octahedral shape of rough diamond crystal in matrix is typical of the mineral. Its lustrous faces also indicate that this crystal is from a primary deposit.

Through studies of carbon isotope ratios (similar to the methodology used in carbon dating, except with the stable isotopes C-12 and C-13), it has been shown that the carbon found in diamonds comes from both inorganic and organic sources. Some diamonds, known as harzburgitic, are formed from inorganic carbon originally found deep in the Earth's mantle. In contrast, eclogitic diamonds contain organic carbon from organic detritus that has been pushed down from the surface of the Earth's crust through subduction before transforming into diamond. These two different source carbons have measurably different 13C:12C ratios. Diamonds that have come to the Earth's surface are generally very old, ranging from under 1 billion to 3.3 billion years old.

The high pressure and temperature required for diamond formation also occur during meteorite impact. Tiny diamonds, known as microdiamonds or nanodiamonds, have been found in meteorite impact craters. These can be used as one indicator of ancient impact craters.

Diamonds formed in extraterrestrial space, then deposited on earth by meteorites, have been found in South America and Africa.

Diamonds are usually brought to the Earth's surface or closer to it by volcanic action and dispersed in an area by water erosion or the action of glaciers. The latter are usually not in high enough concentrations to make them commercially viable sources of diamonds.

Volcanic pipes that reach 150 km or more are relatively rare, but they are the ancient conduits of magma that transported diamonds closer to the surface, where they can be mined.

Certain minirals which are formed and transported from the depths in the same conditions as diamonds, are used as indicators by prospectors looking for sources of diamonds. The most common ones are chromian garnets (usually bright red Cr-pyrope, and occasionally green ugrandite-series garnets), eclogitic garnets, orange Ti-pyrope, red high-Cr spinels, dark chromite, bright green Cr-diopside, glassy green olivine, black picroilmenite, and magnetite.

Every natural diamond is immensely old, formed long before dinosaurs roamed the earth. The youngest diamond is 900 million years old, and the oldest is 3.2 billion years old.

Are Diamonds Really Forever ?

In the past, the Greeks and the Romans thought that the diamonds were tears of Gods and small pieces of stars. There were also the Hindus, who thought that the diamonds had so much power that they put diamonds in the eyes of some of their statues. Other people believed that an unapproachable valley in Central Asia covered by diamonds existed. One said that this valley was "kept by birds of prey and protected by snakes of mortal stare".

Besides believing that diamonds could attract luck and success, people also thought that they could defy the astrological events. Many people used them as jewels, supposing they would be increasing their sexual power and capacity to attract. Even Plato wrote about diamonds, describing them as living creatures, impersonating divine spirits. Until the 15th century, only kings were allowed to use diamonds, having them as a symbol of courage, power and invincibility. But as the centuries passed by, the diamond started to acquire its status of sublime proof of love. Currently, they are related to the love, romance and myth.

We probably will never know when the first diamond was discovered, but we do know that, from the ancient times to the 18th century, all the diamonds of the world came from India. From the period of the Roman Empire to the appearance of the first Europeans to India, in the beginning of the 16th century, the commercial relations between Europe and Eastern Asia bloomed.

One of the main routes of the diamond commerce was in Venice. The city became the most important mercantile republic of the western world. It enjoyed the monopoly of the commerce of the diamond course to the main cities of the south of Germany until its final destiny, Brussels. Since this city became the final phase of the commercial route, it became a promising centre of diamond stature, and the reputation of the city in this sector did not stop increasing. Even though Brussels maintained their predominance until the end of the 14th century, they began to decline in a lapse of fifty years. The diamond trade and numerous other economic activities of Brussels were moved progressively to the city of Ambers, which offered more recent and better facilities for the communications and the commercial exchange. In 1866, the first diamond in South Africa was discovered. Following this was the discovery of the deposits of Kimberley few years later, giving birth to the fabulous era of Kimberley.

The word diamond comes from the Greek word ' adamas ', meaning invincible, and ' diaphanes ', that means transparent. In the past centuries, people believed that a diamond could reattach a wrecked marriage. It was used also in battles as a symbol of courage.

Even though the diamond is the hardest rock known by men, it is the only precious gem with only one element: carbon. Nevertheless, it can only be melted when exposed to a temperature of 5500 degrees Celsius! Billions of years before, the basic forces of heat and pressure miraculously transformed the carbon into diamond through volcano lava underneath the earth. In some way, this volcanic mass was expelled out of the earthly crust, cooling soon to be found as diamonds in rudimentary form. No acid can destroy them, and they are capable to cut anything on Earth, therefore, they only can be cut with themselves.

However, are the diamonds really forever? If they appeared miraculously, can they be destroyed? As incredible as it may seem, the small diamond that adorn the ring that you gave your wife will probably last forever - at least while Earth exists. They are the most resistant minerals of the planet, and only can be melted when displayed to a temperature of 5500°C. The problem is that the global atmosphere will never achieve this high temperature, even if it was to be hit by an enormous meteor that would eliminate all forms of life. They only would melt if, one day, the planet literally entered the Sun, which has a temperature of 5800°C. The curious thing is that, according to astronomers, in 7,5 billion years our planet will actually enter the Sun, when the star will be next to death. If you think diamonds will disappear then, you might be wrong. When such episode happens, the temperature of the Sun will lower to about 3000°C. That means that even when Earth reaches an atmosphere as hot and dense as Mercury’s atmosphere, we will still be able to find some small diamonds spread around.

The Diamond

the diamond is one of the best-known and most sought-after gemstones. Diamonds have been known to mankind and used as decorative items since ancient times; some of the earliest references can be traced to the Indians. Diamond's hardness and high dispersion of light make it useful for industrial applications and jewelry. One of the characteristics

of diamonds that make them so desirable as jewelry is their tendency to disperse white light into its component colors, giving the diamond its characteristic "fire." Diamonds are such a highly traded commodity that multiple organizations have been created for grading and certifying diamonds based on the four Cs which are carat, cut, color, and clarity. Other characteristics, such as shape and presence or lack of fluorescence also affect the desirability and thus the value of a diamond used for jewelry. Perhaps the most famous use of a diamond in jewelry is its use in engagement rings. This use became popular in the early to mid 1900's due to an advertisement campaign by the De Beers company, though diamond rings were used to symbolize engagements since at least the 15th century. The diamond's high value has also been the driving force behind dictators and revolutionary entities, especially in Africa, using slave labor to mine blood diamonds to fund conflicts.

Selecting Diamonds

Diamonds are graded for certification by laboratories using grading criteria. Four ofthese criteria are critical to understand when making a diamond purchase orinvestment. Known as the “Four C’s” these criteria are: color, cut, clarity and carat.

Color is the result of the composition of a diamond and it does not change. When a jeweler is describing the color of a diamond they are referring to the presence or absence of color in white diamonds. Because a diamond with no color allows maximum light to pass through, colorless diamonds are preferred for their sparkle. Cut refers to a diamonds reflective quality. Most diamonds are cut with 58 facets. The brilliance of diamonds is heavily dependent on the cut. The different angles and the finish of a diamond determine its ability to reflect light and cause its brilliance and fire. Remember that the cut of a diamond can have an impact on its durability as well as its beauty. Some cutting faults can make a diamond prone to breakage. A diamond that is cut too thin can also cause light to leak out of the back and the diamond will lose some of the sparkle and appear not to shine. So, as you can see the Cut is probably the most important of the Four C’s.

During the formation process, inner flaws, or inclusions occur in most diamonds. The
number and size of these inclusions determine what is referred to as the clarity of a diamond. Diamonds that are clear create more brilliance and therefore are rarer and highly priced. To be considered “flawless”, a diamond must have no surface or internal imperfections visible upon being viewed by a skilled diamond grader using 10 power magnifications.

Carat is the unit of weight by which diamonds are measured. One carat is equal to 200 milligrams. A carat is divided into 100 segments called points. 150 points would equal one and a half carats. When you go to the store to make that all important diamond purchase, do not be shy! Ask questions, get the answers needed to make an informed purchase. Shopping for certified diamonds enables you to make an informed selection. Knowing the “four C’s” allows you to comparison shop and purchase the best diamond at a fair price. But, before making a purchase, shop around and decide what shapes and styles really appeal to you.

Enjoy your diamond for years to come!

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