hardest known mineral on our planet; the only mineral with the hardness
grade 10 at the Mohs ten-degree scale of mineral hardness.
Diamonds were formed by the impact of high temperatures and pressure in
molten rocks inside the Earth’s crust at the depth between 100 – 160
km. Thanks to volcanic eruptions, they got closer to the Earth surface
through so-called volcanic pipes. The youngest diamonds are old
approximately 100 million years; the oldest ones up to 1. 2 billion
years. Nowadays, the conditions for formation of new natural diamonds
do not exist on the Earth any more. The first mentions about findings
and mining of raw diamonds come from India, which was the only source
of diamonds till the 18th century.
Nowadays, we can process diamonds by cutting into various shapes. The
most frequently used is the classical round cut, so-called brilliant
(at least 56 facets + top table). This is the basis for the most common name of cut diamonds - brilliants
To evaluate quality of cut brilliants, the main criteria are so-called
4 Cs (from the English Carat, Clarity, Colour, Cut); i.e. weight in
carats, clarity, colours and cut of the stone.
As the only one from natural precious stones, it features in all colour tints, especially in the white colour.
Thanks to their hardness, diamonds were considered mysterious stones in
the ancient era; in the ancient legends, they are spoken about as tears
of gods fallen on the Earth.