Hard Fact: From all the diamonds mined the world over, only about 20% actually get used in jewelry.

Yup, you read that right. Jewelry grade diamonds are only about 20% of the total diamonds mined around the world. The rest are either too dull or opaque or just downright financially unviable to be converted into the sparkling stones required for jewelry. Now before you start wondering what happens to the remaining 80% of the diamonds mined, know that diamonds are mainly classified into two kinds – jewelry grade and industrial grade.

While the jewelry grade diamonds are useful only as objects of desire, the industrial diamonds find multitude of uses in almost every technological sector across the globe. Wondering where? Let’s take a look…

High Quality Audio: I am sure you did not see that one coming. Unbelievable, but true.Apparently sound travels a lot faster in diamonds than it does in air. Furthermore, diamonds are unbelievably hard, so when they vibrate, they do not suffer wear and tear. When converted into a really slim dome, they can reproduce top quality sound without any distortion.

Industrial Abrasives:The ultimate combination of hardness and toughness of the diamonds make them ideal for a number of industrial applications such as grinding, polishing and cutting. After jewelry, perhaps the second highest use of diamonds is as abrasives. Extremely small diamonds or grinded diamond powderare installed into a number of tools including drill bits, grinding wheels, metal and diamond saws. Most of the diamond cutting and polishing tools themselves use such diamonds or diamond based powder. After all, only a diamond can cut a diamond.

Semiconductors: Diamond’s impressive chemical, thermal and electronic properties make it the ultimate semiconductor material. Due to diamond’s thermal conductivity, diamonds can tolerate extremely high temperature without getting too hot. Their ability to dissipate heat combined with ability to let electrons travel really fast, allow diamonds to tolerate high voltages before breaking down.

Engraving:Diamond is the hardest materialknown to man. There are several other hard metals and stones other than diamonds, but none come close to the hardness of diamonds. In other words, nothing can scratch the surface of diamonds. So, once again, diamonds are the natural choice for any kind of engraving on other materials. Be it quartz, granite or any other stones, diamonds are used to create beautiful styles, patterns, shapes and even to give them necessary finishingdesiredfor jewelry and other decorative applications.

Interesting Trivia: In earlier times, diamonds were believed to have medicinal properties, especially against poisons and certain deadly diseases such as the plague.

Bearings: When low friction is required, bearings are normally the chosen solution. But what if the bearings needed are really teeny weeny and cannot be changed frequently? Diamonds come in handy in such cases. Their high durability and resistance to abrasion make them just perfect for use in such micro ball bearings.

Diamond Coatings: Once again, it is the high durability of diamonds that is in demand here. For highly sensitive parts of machines, diamonds are converted into vapor form and then the vapor is sprayed on to such parts. This gives them durability that no other coating can provide.

These are just a few of the better known and more widely used applications of diamonds. Scientists across the globe are of course finding many many more applications of diamond as a super technological material every day.

Would it not be cool if we could take some big lumps of coal, apply ultra-high pressure and temperature to it, and get gorgeous diamonds? We would all be rich overnight. Unfortunately, converting coal to diamond can only happen in the movies. Then again may be the Superman can do it with his unreal superpowers.
HARD FACT: DIAMONDS DO NOT FORM FROM COAL
Yup, that’s true – diamonds do not come from coal. They might be found in some coal mines somewhere, but there’s no way that coal might become diamond.
How do diamonds actually form?
For starters, let us understand that both coal and diamonds are made of carbon (though diamond is purer). Yes, you read that right. Both have the same basic material at their cores. However, while coal is only black with zero reflective qualities, diamonds come in a range of colors and have very high reflective indices.

It takes ultra-high pressure,approximately 50 Kilo bars, and extreme temperature, in excess of 1000 degrees Celsius, to form a diamond. Such pressures and temperatures are only possible deep in the earth’s crust – somewhere between 140 and 190 kilometers. There would have to be some form of carbon available deep down there, but that would not necessarily be coal.

Interesting Trivia: Diamonds were formed deep in the earth’s crust somewhere between 600 millionto 3.3 billion years ago. That’s means the youngest diamonds we hold in our hands today were formed way before the dinosaurs ruled the earth.

Actually, coal is rarely ever present that deep below the surface. Coal is usually found at just about 3.2 kilometers underneath the surface. Moreover, coal is formed from plant / vegetation sediments at much lower pressure and temperatures.

Luckily, that would not be required as the diamonds normally get pushed closer to the surface due to a special kind of volcanic eruptions or earthquakes. Now don’t go about thinking that every time there is a volcanic eruption, there will be diamonds spewed out of the earth for the picking. To the contrary, there is no recorded recent volcanic eruption that has brought diamonds to the surface.

That’s because the diamond bearing crust (or mantle as it is correctly known) is much deeper than most currently active volcanic tubes. In other words, diamond bearing regions of the earth came to have those diamonds hundreds of thousands of years ago when there were massive and deep crust volcanic activities thereabouts.

Well, that’s all about how diamonds are formed and come to the surface of the earth to reach us. Next up, we will take a look at the long history of man’s love with this most precious of stones.