how hard diamonds and diamond physical properties

Modern science and technology, the means to explore the formation of diamond provides new ideas and methods. Diamond is the hardest, most simple ingredients gem, which is composed of carbon atoms, with a cubic structure of natural crystals. Its composition and our diamond hole saw  common coal, pencil lead, and the same constituent sugars, carbon at a higher temperature and pressure, the crystallization of graphite (black), and in high temperature, high pressure and reducing environment (usually it is one kind of oxygen environment) in the crystallization of precious diamonds (white). In order to facilitate the understanding of the origin of diamonds, first look at the original rock containing diamonds.
Since diamonds were discovered in India, we have been hearing people in the river, riverside picked up the story of the diamond, which is due in the river somewhere upstream of diamond original rock, weathered, broken, with the water being brought diamonds to downstream areas, than the major diamond buried in the gravel. What is the original rock diamonds? 1870 people on a farm in South Africa dug in loess diamonds, diamonds  carbide saw blades dug from the riverbed thereafter transferred to the loess, loess Here is rock hard, dark blue, it is the diamond original rock - kimberlite (kimberlite). What is kimberlite?
Kimberlite is formed deep in the earth, contains a lot of carbon dioxide and other volatile components of alkaline ultramafic volcanic rocks often contain such deep from the earth peridotite, eclogite fragments, the main mineral ingredients include olives Stone, phlogopite, carbonate, pyroxene, garnet and so on. Studies have shown that the formation of kimberlite magma deep in the earth 150 km or less. Because of this rock was discovered first in Kimberley, South Africa, so named by the names.
Another original rock containing diamonds known lamproite (lamproite), it is a too alkaline magnesia volcanic rock, mainly composed of leucite, volcanic glass formed may contain pyroxene, olivine and other minerals, typical origin of Western Australia Argyle (Argyle).
Scientists from around the world through a different pair of diamond mines and mineral inclusions natively study found that diamond formation conditions generally pressure 4.5-6.0Gpa (equivalent to 150-200km depth) and a temperature of 1100-1500 degrees Celsius. Although in theory, diamonds can be formed in various periods of history of the earth / phase, while current exploitation of mines, most of the diamonds formed mainly in the 3.3 billion years ago and 12-17 million years these two periods. Some, such as the South African diamond age of about 4.5 billion, indicating that these diamonds in the Earth already begun shortly after the birth of the deep in the earth crystal diamond is the world's oldest gems.
Diamond formation requires a long historical process, which is mainly produced from diamond on Earth ancient stable continental regions can be confirmed. In addition, the stars on the planet extraterrestrial impact, resulting in instantaneous temperature, high pressure, but also the formation of diamonds, such as 1988 years ago, the Soviet Academy of Sciences reported that diamonds were discovered in meteorites, but this effect has no economic value of a diamond formation.
Rare diamonds mainly in two types of rocks, a class is peridotite categories, one is the eclogite, but only the former has economic significance. Diamond-bearing peridotite, so far discovered two types: kimberlite (kimberlite) (name derives from South Africa was a place name - Kimberley) and lamproite (lamproite), both in the rocks are made from volcanic eruptions effect generated deep in the earth's rocks formed by the volcanic activity was brought to the surface or shallow earth, this magmatic rocks mostly tubular output, so called "tube mine" (ie, primary ore).
Diamond-bearing kimberlite or lamproite exposed at the surface, through the wind and rain outside forces such as the role of Earth's weathered, broken, washed in water, the crushing of the original rock drill is brought to bed together, and even the coast Strip the  hole saw blades product down, forming alluvial sand deposits (or secondary deposits).
Just how hard [Diamond]
Diamond is the hardest substance in nature, is a Mohs hardness of 10 unique mineral, it is known as "the king of hardness." Its anti-friction hardness of corundum 140 times, 1100 times more than quartz and thus its unparalleled hardness can be imagined.
It should be pointed out: the hardness of diamonds here that particularly large, it is the ability to resist external forces scored; but it also has a brittle, afraid to hit, strike it or will stumble along its cleavage after crushing. So even though the diamond is the hardest substance in nature, but it is also possible to use a hammer to crack it. Therefore, wearing diamond jewelry, you should pay special attention to protection.