How are natural diamonds formed?

Diamonds are considered the oldest treasures in the world: they were formed more than 3,3 billion years ago at a depth of 200 km below the Earth’s surface. Under conditions of extreme heat (900 to 1300 degrees Celsius) and pressure (45 to 60 kilobars), carbon atoms crystallize to form diamonds. Diamonds take millions of years to form, and geologists believe the most recent diamonds may be up to 45 million years old. Changes in temperature and pressure can significantly affect the formation of diamonds, and if conditions are not ideal, it can cause the diamonds to dissolve. Molten kimberlite (also known as magma) also forms in the Earth’s upper mantle under conditions of intense heat and pressure, causing it to expand at high rates. This expansion causes magma to erupt, pushing it to the Earth’s surface and carrying diamond-bearing rocks with it. These types of “eruptions” have not occurred recently and are believed to have occurred at a time when the Earth was naturally hotter, making such eruptions more likely. Moving at incredible speeds, the erupted magma forms a pipe leading to the surface of the Earth. As the magma cools, it hardens to form a rock called Kimberlite, the most important source of diamonds. Kimberlite occurs in vertical structures known as kimberlite pipes. Kimberlite gets its name from the city of Kimberley in South Africa, where the first diamonds were found in this type of rock. Although kimberlite pipes are the most important source of diamonds, it is estimated that only 1 in 200 kimberlite pipes contain gem-quality diamonds. This demonstrates the rarity of diamonds and serves as a reminder that a diamond is a unique gift from Mother Nature, slowly formed and extremely valuable due to its rarity. Diamonds are mined using a variety of methods, and on average 250 tons of ore are mined to produce a one-carat gem-quality diamond. The ancient Greeks believed that diamonds were the tears of the gods. , and that they had mystical and magical properties. Although the perception of diamonds has changed somewhat since then, these gems have retained their ability to enchant all who look at them. With expert levels of craftsmanship, Shimansky diamond cutters and polishers bring a rough diamond to life and bring out its brilliance, flame and sparkle – and most importantly, unleash its full potential. The word diamond comes from the Greek word Adamas, which means indestructible. The strongest material known to man, diamond is composed entirely of carbon, making it the only gemstone composed of a single element (it is 99,95% carbon). The remaining 0,5% is believed to consist of trace elements that can affect the color of a diamond, but are not part of its chemical structure or molecular composition. Carbon, found in abundance, comes in many forms: the difference between a diamond and a lump of coal essentially lies in their molecular structure. Coal or charcoal has an amorphous structure and contains organic molecules of decomposed plant and animal matter. Like diamonds, it formed deep in the earth’s crust. However, diamonds have a crystalline structure that resembles a pyramid shape. When a diamond is formed, each of its carbon atoms bonds with four other carbon atoms. This means that each atom is essentially involved in four extremely strong covalent bonds. It is these bonds that make diamonds 58 times harder than any other substance found in nature. Diamonds are found in various parts of the world, but are most common in Africa, South America and parts of the East. It is believed that the first diamonds were discovered in the rivers and streams of India as early as the 1700th century BC. Brazil became an important source of diamonds in the 1867s, and it was not until XNUMX that diamonds were discovered in Kimberley, South Africa. Today, South Africa is one of the most famous and richest diamond-producing countries in the world. Shimansky’s team of experts can see the potential of a diamond while it is still in its rough form. To transform a raw stone into a mesmerizing spectacle of light in a jewelry creation requires great precision, skill and attention to detail from our master diamond cutters and polishers. Beautiful and rare, the unique way a diamond is shaped gives it unique qualities as well as the ability to shine with unrivaled brilliance. The most precious of gems, the journey of a diamond from the core of the Earth to the finger of the person it is intended for is not only fascinating, but also magical. Diamonds are a rare, but at the same time quite widespread mineral. Industrial diamond deposits are known on all continents except Antarctica. Several types of diamond deposits are known. Several thousand years ago, diamonds were mined on an industrial scale from alluvial deposits. It was only towards the end of the 19th century, when diamond-bearing kimberlite pipes were first discovered, that it became clear that diamonds do not form in river sediments. There is still no exact scientific data on the origin and age of diamonds. Scientists are considering several hypotheses: magmatic, mantle, meteorite, fluid, and there are even several exotic theories. Most are inclined to the magmatic and mantle theories, namely that carbon atoms under high pressure (usually from 45000 to 60000 atmospheres) and at great depth (about 125 to 200 km) form a cubic crystal lattice – the diamond itself. Diamond formation occurred at temperatures from 900 to 1300 degrees Celsius. Rocks are forced to the surface by volcanic magma during the formation of so-called “explosion tubes.”

Arrangement of carbon atoms in diamond	Arrangement of carbon atoms in graphite

The age of diamonds, according to some research data, is estimated from 900 million to 4,25 billion years. Meteorite diamonds are known to be of extraterrestrial, possibly presolar, origin. Diamonds are also formed during impact metamorphism during the fall of large meteorites, for example, in the Popigai astrobleme in northern Siberia. Such diamonds are called “impact” from the English. impact – “collision”, “impact”. Diamonds have also been found in the roof rocks of ultra-high-pressure metamorphism associations, such as the Kumdykul diamond deposit in the Kokchetav massif in Kazakhstan.

metamorphic diamonds	diamonds of igneous origin

Both impact and metamorphic diamonds sometimes form very large deposits, with large reserves and high concentrations. But in these types of deposits, the diamonds are so small that they have no industrial value. Commercial diamond deposits are associated with kimberlite and lamproite pipes associated with ancient cratons. The main deposits of this type are known in Africa, Russia, Australia and Canada. Recently, paleogeologists have proposed a new theory about the origin of diamond-bearing rocks. Using this theory, it is possible to calculate areas with diamond deposits similar to those in Africa and Yakutia. Diamond mining in alluvial deposits has been carried out for thousands of years, and only at the end of the 19th century was the connection between diamond deposits and kimberlite pipes established. Under strong pressure in the Earth’s mantle, a cubic lattice is formed from carbon atoms, and diamonds are obtained, which, millions of years later, come to the surface under gas pressure, forming kimberlite pipes. A group of scientists from various countries at the University of Oslo, under the leadership of Professor T. Torsvik, put forward a hypothesis that will make it possible to study the little-studied layers of much younger kimberlite deposits from the period of 500 – 200 million years, in contrast to the known ones, whose age is about two and a half billion years . According to this hypothesis, mantle plumes are columns of mantle matter that were formed at the boundary of the core and mantle at a depth of 3 thousand km. Using seismic tomography, the zones with the location of plumes were calculated – Pacific and African. Moreover, calculations show the immobility of these zones for two hundred or more million years. An interesting situation arose: while the plumes remained motionless, the continents moved, and since the kimberlite outcrops depended on the plumes, their (kimberlites) location can be calculated. Therefore, scientists have compiled maps that indicate how the plumes were located over different periods of time. It is believed that this research could lead to greater prospects for diamond exploration. Because now it is possible to limit search and research work to zones that passed above the plumes. Scientists will have to detail the map of the movement of continents in relation to mantle plumes over the past half a billion years.

About diamonds

Diamond color
The most important characteristic that affects its appearance. Diamond clarity
Read about inclusions in diamonds and their purity, characteristics that affect their value. Diamond weight
Measured in carats, a small unit of measurement that corresponds to 0,2 grams. Cut quality
Cut quality is one of the most important characteristics of a diamond. Certificates
Our company can use diamonds with GIA, HRD and IGI certificates. Cut shape
The shape of a diamond determines its unique properties.