Friday, August 9, 2019

how are diamonds formed

how are diamonds formed worldwide

how are diamonds formed: Many people assume that diamonds are created by the metamorphism of coal. This is not true at all. Loose diamonds are discovered in diamond mines all over the world. Let's see how these beautiful stones came to the surface.

how are diamonds formed
how are diamonds formed
Let's start with natural diamonds. These are formed and found about 100 miles below the earth's surface. At this depth, carbon-rich rocks are provided with sufficient heat and pressure to melt. The high temperatures are generated by the earth's mantle, a layer made of molten rock that is compressed by the pressure of miles and miles of earth on top. This layer keeps churning and when the conditions are just perfect, molten rock can move upwards and cool down over time. These parts of cooled molten rock can contain diamonds. Needless to say, this is a process that takes hundreds and perhaps thousands of years.

Education and growth how are diamonds formed

Diamonds in the mantle form through a metasomatic process in which a C-O-H-N-S liquid or melt dissolves minerals in a rock and replaces them with new minerals. (The vague term C-O-H-N-S is commonly used because the exact composition is not known.) Diamonds form from this liquid by reduction of oxidized carbon (e.g., CO2 or CO3) or oxidation of a reduced phase such as methane.

Carbon sources

The amount of carbon in the jacket is not well limited, but the concentration is estimated at 0.5 to 1 parts per thousand. [55] It has two stable isotopes, 12 ° C and 13 ° C, in a mass ratio of approximately 99: 1. This ratio has a wide range in meteorites, which means that it was probably also wide in the early earth. It can also be changed by surface processes such as photosynthesis. The fraction is generally compared to a standard sample with a ratio of 813C expressed in parts per thousand. Common rocks of the mantle such as basalt, carbonatite and kimberlite have ratios between −8 and −2

Surface distribution

Geological provinces of the world. The pink and orange areas are shields and platforms, which together form cratons.

Diamonds are too far from evenly distributed over the earth. In developin g world a rule of thumb as  known as Clifford's rule in states that they are almost always found in kimberlites on the oldest part of cratons, the stable cores of continents with a typical age of 2.5 billion years or more. The Argyle diamond mine in Australia, the largest producer of weight-based diamonds in the world, is located in a mobile belt, also known as an orogenic belt, a weaker zone around the central kraton that has undergone compression tectonics. The guest stone is lamproiet instead of kimberlite. Lamp roses with diamonds that are not economically viable are also found in the United States, India and Australia. [55] In addition, diamonds in the Wawa belt of the Superior province of Canada and microdiamonds in the island arch of Japan are found in a type of rock called lamprophyre.

Read also about diamond uses


Kimberlites can be found in narrow (1 to 4 meters) dikes and sills, and in pipes with diameters ranging from approximately 75 m to 1.5 km. Fresh stone is dark blueish green to greenish gray, but quickly turns brown and crumbles after exposure. [62] It is a hybrid rock with a chaotic mixture of small minerals and rock fragments (class) up to the size of watermelons. They are a mixture of xenocrysts and xenolites (minerals and rocks carried by the lower crust and mantle), pieces of surface rock, altered minerals such as serpentine and new minerals that crystallized during the eruption. The texture varies with depth. The composition forms a continuum with carbonatites, but these have too much oxygen to allow carbon to exist in a pure form. Instead, it is trapped in the mineral calcite (CaCO3).

Formation in the room

NASA researchers have discovered large numbers of nanodiamonds in some meteorites. (Nanodiamonds are diamonds that are a few nanometers - billionths of a meter in diameter.) Approximately three percent of the carbon in these meteorites is in the form of nanodiamonds about how are diamonds formed. These diamonds are too small for use as gems or industrial abrasives; however, they are a source of diamond material.

Smithsonian researchers also found large numbers of small diamonds when they carved a sample from the Allen Hills meteorite. These diamonds in meteorites are thought to have formed in space by high-speed collisions, similar to how diamonds form at collision sites on Earth.

What do loose diamonds during production have in common with a pile of coal? More than you might think; in geological terms, loose diamonds are nothing more than glorified chunks of coal. The differences are:

- the arrangement of the carbon atoms
- how each material is formed

Even when it comes to diamond formation, the difference between processes is one of degree rather than mechanics. Here is some interesting information for potential buyers of wholesale certified diamonds.

Carbon is carbon

Some may remember an episode of the old 1950s "Superman" TV series in which Clark Kent created a diamond by compacting a lump of coal in his fist. Although it is doubtful that even the "Man of Steel" can exert such supernatural geological forces deep within the earth, the illustrated concept was essentially correct - those loose diamonds that end up with diamond traders selling them to jewelers are made of carbon exposed to extremely high pressures of 60 kilobars (for comparison, that is 60,000 times the normal air pressure at sea level) and temperatures of more than 2300 degrees Fahrenheit (structural steel melts at around 1520 ° F)!

The pressure and heat needed to make diamond are only found in the Earth's lithosphere, where the crust meets the upper mantle - about 90 - 240 miles below the surface. Diamonds can also arise when a meteorite touches the earth's surface, creates similar conditions or is passed inside the meteorite (some diamonds come from space!).

Coal, on the other hand, is formed from the rotting remains of ancient plant material that is also compressed by geological forces, but much closer to the surface. In chemical terms, carbon atoms that form carbon molecules are arranged in a flat, hexagonal pattern, making them much brittle. In diamonds, however, they are arranged in a tetrahedral or box-like structure about how are diamonds formed. This explains the hardness of loose diamonds.

Can one change the other?

Ultimately, if a coal layer sinks into the earth low enough and is exposed to high pressure and temperature, it can become diamond. Theoretically, diamond can also turn into coal if it is kept free from chemical reactions that color the gems and stabilize the surface, and then be subjected to a vacuum. However, this is unlikely outside of controlled laboratory conditions.

The process of making stones in a laboratory requires a mixture of carbon and graphite and a small amount of seed diamonds. This mixture is then placed in a machine core that is under a pressure of up to 800,000 pounds per square inch at a temperature of more than 1000 degrees. Once a diamond is formed, some manufacturers add a protective coating to improve the light-reflecting properties of the stone. This protective layer is able to cure the stones even further. It is clear that the process of making lab diamonds is almost the same as that of a natural diamond - apart from a few additions from different manufacturers to offer added value to their products. In some cases, these additions are unique to the specific manufacturers. This ability to control the circumstances makes it simpler, much more economical and much less time-consuming.

Most of these pipes do not contain diamonds, or contain such a small amount of diamonds that they are not of commercial interest. However, open-pit and underground mines are developed in these pipes when they contain sufficient diamonds for profitable mining. Diamonds are also weathered and eroded from some of these pipes. Those diamonds are now in the sedimentary (placer) deposits of streams and coastlines about how are diamonds formed.

All three diamonds some bearing rocks (kimberlite, lamproiet and lamprophyre) and lack certain minerals (melilite and kalsilite) which are incompatible with diamond formation. In kimberlite, olivine is large and striking, while lamproiet has Ti-phlogopite and lamprophyre biotite and amphibole. They are all derived from magma types that quickly burst out of small amounts of melt, are rich in volatile substances and magnesium oxide and oxidize less than more conventional mantle melts such as basalt. These properties ensure that the melts carry diamonds to the surface before they dissolve.

A more recent study investigated the origin of blue, boron-containing diamonds that formed at a depth of up to 650 miles (400 miles). These super-deep diamonds also contain inclusions that indicate they were derived from subjugated sea crust.

Is coal involved? Coal is not a likely carbon source for this diamond formation process. The most likely carbon sources of ocean plate subduction are carbonate rocks such as limestone, marble, and dolomite, and possibly plant waste particles in offshore sediments.

Thanks for reading about how are diamonds formed

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