How are diamonds formed in nature?

For a long time, diamond has become the standard of strength, invincibility and stability. However, it is helpful to be aware of how diamonds are formed.

Not so few people at least once in their lives held jewelry with diamonds in their hands. But with regard to the origin of the reference gem, the situation is much worse. Even experienced mineralogists and geologists cannot say with complete certainty which version is true.

Diamonds became known long before our era. It was impossible to pass a stone with such unusual properties.

One of the old legends says that:

• diamond crystals are living beings;
• they can be of different genders;
• these organisms "consume the celestial dew";
• they can grow in size and even multiply.

Ancient Indian mythology claimed that a diamond appears in nature when five basic natural principles are combined. These include:

• air;
• water;
• Earth;
• sky;
• energy.

In ancient manuscripts, they immediately began to note that the diamond is very hard and has an extraordinary brilliance. It has often been written that this mineral can appear "on the rock, in the sea and on the hills above the gold mines."

Legends about Sindbad the Sailor say that somewhere there is a rather deep gorge, at the bottom of which the primary deposits of diamonds are hidden. But, of course, all this very weakly correlated with reality.

We must pay tribute to the people of antiquity and the Middle Ages. The search for the real reason for the formation of a diamond shows that human thought has never stood still. And yet the first serious versions of its appearance could be put forward only after 1797 - it was then that the chemical composition of the mineral was precisely established.

A little later, it was discovered that the difference between diamond, graphite and various types of coal is due to the arrangement of atoms within the crystal lattices.

The essence of the concept is the emergence of these minerals as a result of the movement of magma. It is assumed that most of them appeared not earlier than 2.5 billion and not later than 100 million years ago. This happened at a depth of about 200 km. There, graphite was simultaneously affected by a high temperature of about 1,000 degrees and a pressure of 50,000 atmospheres.

One of the versions of the version implies that semi-precious stones were formed already on the surface of the earth.

This happened as a result of lava solidification upon contact with air. The problem is that the temperature and pressure in such a situation are not too high. For this reason, this concept is not popular with professionals.

There is an alternative assumption according to which gems are formed from ultrabasic rocks.

Only later, when the magma rose upward, a stone was thrown out with it. The overwhelming majority of geologists are inclined towards this approach. An intermediate version is that diamonds are formed when magma has already begun to move upward, but has not yet reached the vent.

Such changes in the structure significantly strengthen the stone itself and give it the qualities so valued in the commodity market.

Former diamond reserves associated with ancient deposits and kimberlite pipes are increasingly rare. And the need for stones is great. Sometimes the inhabitants of volcanic regions, some time after the eruptions, extract the hardest mineral from the hardened lava. But the conditions required for its appearance are obtained not only due to volcanic processes, while some diamond researchers pay attention not only to the depths of the Earth, but also upward.

Repeatedly, even when examining pieces of meteorites, whole diamonds (or their individual particles) were found. The quality of these minerals was excellent.

Once, when a meteorite fell in the United States, precious stones were found in the walls of the crater. But they were somewhat different from the usual options. The difference, according to some sources, concerns the structure of the crystal lattice - it is not reflected in the external appearance.

Some experts believe that diamonds are already inside the meteorites. When they are destroyed, the stones are “free”.

A more popular idea is that the stone appears already upon impact with the earth's surface. This process provokes the release of significant mechanical and thermal energy.

For this reason, both the temperature and the pressure in the center (where the crater will remain) rise sharply. These factors lead to the characteristic transformation of carbon.

Spectrographic observations have shown that gaseous carbon (in pure form or in conjunction with nitrogen, hydrogen) is present in the Sun's atmosphere. Astronomers and cosmologists believe that this element was also in the colossal clots of gas, dust, which became the harbingers of all planets. On cooling, the gases liquefied. Gradually, liquid substances were distributed over the mass: the heavier ones sank down, and the light ones float up.

Liquid magmatic masses in the initial period of the Earth's development easily broke through a thin layer of the earth's crust. Carbon actively reacted with hydrogen. As a result, the earth's crust gradually lost this chemical element.

At the present stage of the geological history of our planet, it accounts for approximately 1%. Such an excursion allows us to draw an outwardly paradoxical conclusion: there are no deep contradictions between volcanic and cosmic hypotheses.

The only difference is in the ways in which she got to a particular place. Experts believe that most of the carbon is now located in the outer part of the mantle, because there high temperature and pressure lead to the formation of compounds of the basic substance with heavy metals. But some of the carbon atoms are attached to each other.

Even the famous Vernadsky and Fersman put forward the assumption that this is how diamonds are born. The scheme of geochemical transformations of carbon belongs to two scientists. According to this classical scheme, both diamond and graphite are concentrated mainly in the lower layers of the lithosphere.

The deepest wells on Earth only reach a depth of 10-12 km. At the same time, the nucleation of diamonds, even according to Fersman's version, occurs at depths of at least 30-40 km. This is the average thickness of the earth's crust. It will not be possible to check the mantle version at the current level of drilling. Returning to the mantle-magmatic version, it is worth pointing out that according to it, carbon can turn into diamonds if:

• a chemically uniform environment will exist for hundreds of millions of years;
• while maintaining weak thermal gradients;
• the pressure will stably exceed 5 thousand Pa.

The corresponding parameters, based on the concepts of modern geology, are achieved at a depth of 100 to 200 km.

Another indispensable condition for "success" is the presence of diatremes or breakthroughs in the earth's crust. On continental platforms, magmatic melt saturated with noticeable quantities of gases can break through it. As a result, the well-known kimberlite pipes are formed.

There is also an alternative fluid version, according to which the strongest mineral crystallizes at a shallower depth. The starting point is the decay of methane or its incomplete oxidation. The oxidizing agent is a mixture of hydrogen, carbon, oxygen and sulfur. Four elements can be in both liquid and gaseous state of aggregation.

It follows from the fluid hypothesis that diamonds can appear at a temperature of 1,000 degrees, acting simultaneously with a pressure of 100 to 500 pascals.

It is impractical to carry out large-scale mining in other places. Over time, geological processes lead to the destruction of the upper part of the primary deposits. Diamonds from there are carried away (and carried away in the past) by flowing water. When the mineral is deposited again, placers appear.

For the mystery of the origin of diamonds, see the next video.