Out of all the things in the world, Marilyn Monroe chose diamonds to be a woman’s best friend, ever wondered why? Precisely speaking, they are incredibly expensive and are also the purest of gems. Diamonds are carbon compounds grilled under too much pressure for too long inside the oven of Earth. So, they are pure carbon and by some uncanny process resemble "coal" in their chemical composition.

They are joined by covalent bonding, with the bonds forming a flexible three-dimensional structure which give diamonds their characteristic toughness. By this structure, each carbon (C) atom is surrounded by 4 other atoms of Carbon making a tetrahedral shape. They have a cubic, crystal structure and is metastable at room temperature. Nonetheless, it barely changes to graphite (the stable form).

The term "Diamond" has its roots in the Greek word "adamao" which means "I subdue" or "unconquerable" suggesting its timelessness. Since 4th century BC up till very long, India was the only source of diamonds for the entire world. It wasn't until the early 18th century, that other locations were discovered like Brazil and in the 1870s, in South Africa. Soon after it was discovered, diamonds became synonymous with love and the people believed that they were parts of the stars or crystallised lightening.

In recent times, diamonds are used in various domestic and industrial uses, owing to its toughness (as industrial metal and glass cutter) and as ornaments for its unique shine and lustre. The industrial grade diamond is used mostly for cutting and polishing.

Diamonds may appear colourless to the naked eye but majority of the diamonds have a slight brown or yellow colour in them. Although, the near colourless or completely colourless diamonds are the most expensive. The colour plays a vital role in determining the cost of a diamond. Rarely other colours like red, black, blue, green, pink, violet, orange and purple are found which are evaluated for more than the regular diamonds.

These natural occurring diamonds are aged around 1 billion to 3.5 billion years. With their depth ranging from 150 to 250 kilometres towards the Earth's mantle. Recently, synthetic diamonds have also come into existence, formed by simulating the required conditions in a laboratory. These synthetic diamonds are so similar that they are almost gem-quality and impossible to differentiate unless you're a gemmologist who is rich enough to buy sophisticated equipment.

Diamonds are measured in carats (ct.) which are further divided into points. Each carat has 100 points (1 carat= 100 points; ½ carat= 50 points). The weight system for the diamond, although, does not hold much significance unless you also consider the cut, colour and clarity of the diamond. This means that a small, yet better quality diamond would cost more than a bigger diamond that lacks lustre, purity and brilliance. This been said, larger diamonds are very rare and hence the rise in price is exponential with rise in carat weight, other factors remaining constant. Hence, the value of a diamond is judged based on its size, colour, weight, clarity and cut.