Diamonds are made purely of carbon atoms arranged in an isometric-hexoctahedral crystal lattice. Being one of the most precious stones, diamonds are 1000 times stronger than rubies or sapphires.
Their superlative physical qualities like hardness, luster, high dispersion index, and high thermal conductivity (900 - 2320 W/m K) makes them useful for jewelry and industrial applications.
They can be identified by their high thermal conductivity and refractive index. About 98% of the natural varieties of this mineral are used for industrial purposes, and rest are used as gemstones.
The Four Cs
Diamonds are examined mainly by the 'four Cs': carat, clarity, color, and cut. They are measured in carats; one carat equals 1/5th of a gram. These gemstones also may show different colors like white, yellow, brown, pink, red, blue, purple, green, violet, and orange. Out of these, the white, yellow, and brown ones are most commonly used.
Formation Process of Diamonds
Diamonds are formed under tremendous heat and pressure. These conditions exist at about 150 to 200 km beneath the Earth's surface, where the temperatures are extremely high ranging from 900º C to 1300º C. For millions of years, carbon atoms deep in the Earth's upper mantle have been exposed to these extreme conditions.
As a result, these atoms combine their cubic molecular form, and they ultimately form diamond crystals. During volcanic eruptions, these crystals eventually make their way to the Earth's surface through pipes and channels.
These passageways contain the magma from the volcano, which rises along with the diamonds, and deposits them on the surface where they are later found and mined. These are known as the primary deposits of diamond. The igneous rock called kimberlite is the most common host of diamonds found in the earliest volcanic pipes.
Some diamonds get washed away either by erosion, or by nearby water bodies, and are thus found near river beds. They are known as alluvial deposits. Millions of years of erosion spread diamonds into streams, rivers, and the seas. Many centuries ago, diamonds were first recognized and mined in India along the rivers Penner, Krishna, and Godavari.
Natural diamond sources have been discovered in 35 countries all across the globe. Russia, Botswana, and South Africa are the major gem quality diamond producers in the world. Australia is one of the world's biggest industrial diamond producers.
So, the next time when you venture into a jewelry store and admire an incredible diamond ring, just think about the time, energy, and resources that have gone into its making, and you'll surely have a better appreciation for it.