How are diamonds formed n why are they only from Africa?

Question

Do they really last forever as they say...?Thanks for the help

Answer 1

How and where are diamonds formed?
Diamonds form between 120-200 kms or 75-120 miles below the earth's surface. According to geologists the first delivery of diamonds was somewhere around 2.5 billion years ago and the most recent was 45 million years ago. That is a long time, my friend! According to science , the carbon that makes diamonds, comes from the melting of pre-existing rocks in the Earth's upper mantle. There is an abundance of carbon atoms in the mantle. Temperature changes in the upper mantle forces the carbon atoms to go deeper where it melts and finally becomes new rock, when the temperature reduces. If other conditions like pressure and chemistry is right then the carbon atoms in the melting crustal rock bond to build diamond crystals.
There is no guarantee that these carbon atoms will turn into diamonds. If the temperature rises or the pressure drops then the diamond crystals may melt partially or totally dissolve. Even if they do form, it takes thousands of years for those diamonds to come anywhere near the surface.


Until the 18th century, India was the only supplier of diamonds in the world. Diamonds were discovered in Africa in the early 19th century and subsequently became the largest producer worldwide, relying on Zaire for industrial diamonds and South Africa for gem quality diamonds. Since the early 80's, Australia has been producing the most diamonds worldwide

Answer 2

Diamonds are formed out of Carbon which is heated by a volcanic eruption and then pushed upward towrd the earths surface at a speed sufficent to cool it quick enough to turn it into a diamond, Diamonds are not only found in Africa but also in India and in the United States, some have been found in Austraila as well but the main producing countries is Africa and India with India being the leader, Murfreesboro, Ar is the only place in the U.S that I know of that has a Diamond mine and it is open to the public to pay a fee and hunt for Diamonds

Answer 3

Diamonds are mined in many parts of the world, but 80% of the stones on the market today come from Angola, Australia, Botswana, Namibia, South Africa, Russia and Zaire. As far as how they are formed, check this URL

http://www.gemsutra.com/diamonds.html

Answer 4

There are diamond mines in Siberia and North America and parts of Asia. I've heard that diamonds can burn because they are made out of carbon like coal. But it would require an extremely high heat. I've never tried it. Few people do. Who wants to burn up their diamonds.

Answer 5

Formation of Diomand -
Diamonds are formed by prolonged exposure of carbon bearing materials to high pressure and temperature. On Earth, the formation of diamonds is possible because there are regions deep within the Earth that are at a high enough pressure and temperature that the formation of diamonds is thermodynamically favorable. Under continental crust, diamonds form starting at depths of about 150 kilometers (90 miles), where pressure is roughly 5 gigapascals and the temperature is around 1200 degrees Celsius (2200 degrees Fahrenheit). Diamond formation under oceanic crust takes place at greater depths because of higher temperatures, which require higher pressure for diamond formation. Long periods of exposure to these high pressures and temperatures allow diamond crystals to grow larger.

The slightly misshapen octahedral shape of this 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 (see plate tectonics) 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.

Diamonds occur most often as euhedral or rounded octahedra and twinned octahedra known as macles or maccles. As diamond's crystal structure has a cubic arrangement of the atoms, they have many facets that belong to a cube, octahedron, rhombicosidodecahedron, tetrakis hexahedron or disdyakis dodecahedron. The crystals can have rounded off and unexpressive edges and can be elongated. Sometimes they are found grown together or form double "twinned" crystals grown together at the surfaces of the octahedron. This is all due to the conditions in which they form. Diamonds (especially those with rounded crystal faces) are commonly found coated in nyf, an opaque gum-like skin.[4]

Diamonds can also form in other natural high-pressure, high-temperature events. Very small diamonds, known as microdiamonds or nanodiamonds, have been found in impact craters where meteors strike the Earth and create shock zones of high pressure and temperature where diamond formation can occur. Microdiamonds are now used as one indicator of ancient meteorite impact sites.

Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are generally mined from volcanic pipes, which are deep in the Earth where the high pressure and temperature enables the formation of the crystals. Afarica is having lot of such mines and hence the production in African counties are more.

As told "Diomands are forever" You have to only maintain it. It will lost for ever for many centuries even.

Answer 6

diamonds are not only from africa two of the bigest were found there
but alot of places have them diamonds are made from high heat and pressure to carbon they are the hardest rock on the scale they can be damadged but it takes alot to do so to cut it or to scratch it or to crack it its a very strong rock its a 7 on the scale which is the highest

Answer 7

They are not just africa, Russia has them, and the US has them in Arkansas.

Formed by heat and pressure on carbon..

Answer 8

It's funny that you asked about it.

I am curious about its value of its gems of diamonds . The difference between fake and genuine.

Answer 9

diamonds are the hardest known gems to mankind and a girls best friend(lol). Actually they are formed when huge amonuts of pressure are concentrated into

Answer 10

EVER BEEN TO ARKANSAS?
GODBLESS