THE DIAMOND AND
ITS HISTORY
Etimology
Many of you would wonder what a diamond is and where it really comes from. There is too much to say about it, but let us go step by step, starting from its etimology.
The word “diamond”comes from the Greek”Adàamanta”, accusative case of Adamas, that at the neginning meant “Very Hard Iron”. Only after Aristoteles this terminology was applied to gems, the term is composed of the privative “a” and of the word “Damac” that means “to tame”. That is why the stone has the meaning of “Untameable”. Even the Romans named it “Adamàntem”. This happened because there was not any hard material able to nick, work or destroy it in ancient times. Also Pliny the Elder exalted its properties in his treatise “Naturalis Historia” in the 1st century AD, by describing it as the most hardest living stone. Having a diamond at that time meant that you had somehow the power on the material itself.
History
The diamond had been known since 3000 AD in the East and appeared in the West after the expeditions of Alexander the Great. There are many histories and legends about this stone and they have arisen from the different populations and cultures that have come in contact with it over time. Some thought that diamonds had healing qualities and advised to use it as a talisman to protect themselves from poisons, bad spells, plague or other serious diseases. Others even thought that diamonds had romantic qualities, it could make love last forever, that’s why couples and lovers preserved it with proud. Anyway, the diamond already had a good saleability because of its extreme rarity at that time, even if gold was considered more precious than diamonds.
About the 10th century, some diamonds were found in Borneo, but unfortunately it was a very small quantity that never started a diamond trade.
About the end of the 16th century, the Brilliant-cut was discovered which started the use of diamonds on rings. Because of its inalterability, the diamond had another meaning: the loyalty of the wedding and eternity in love bound. Moreover, about the end of the 14th century there was the golden age and the town of Anversa became very famous for its Masters of Diamonds, followed by Amsterdam.
About the half of the 17th century, Jean Baptiste Tavernier, explorer and traveller at the service of Luis XIV, discovered the Golconda mine, on the west coast in India. The Koh-l-Noor, the famous Great Moghul’s diamond, was extracted from these mines. The great maritime republics of Genoa and Venice were the two main historic importers from Golconda mines.
About the end of the 16th century, the diamond trade was increasing, especially when the Portugueses reached the Isle of Goa next to India and discovered the greatest diamond basin at that time. In 1720, the Portugueses also discovered diamonds in Brazil next to the river Jequitinhonhas.
When the production of diamonds was running out in Brazil, in 1886 a little girl, daughter of a family emigrated to South Africa was playing with a shining stone that her brother had given to her. A neighbour saw it and thought that it could be a diamond. And so it was. It was the famous diamond “Eureka” that, even if it was not a pure one, it started a huge research which reached its height three years later with one of the most spectacular discovery in history: the known “Star of South Africa”, a 83,50 ct rough diamond, then cut in the shape of a drop weighing 47,75 ct. So, it was the beginning of a new era of prosperity and global trade of diamonds.
Mining and Separation processes
Diamonds are found in so called primary and secondary fields. The primary ones are called Kimberlite pipes and the mining takes place through the excavation in the volcanic pipe. The secondary fields are next to areas of the primary ones, often are made of drifts, where, over the millennia, the primary fields released the diamond that settles on the torrent bottom. The quantity of extracted diamonds has always been paltry and requires substantial investments. From each ton of excavated rock, you get only one carat of diamond. This explains why the diamond price is so high.
Chemical Composition
Diamond, as graphite, is one of the allotropes (chemical elements existing in different shapes) of the carbon: one element can exist in two or more physical shapes, that are different because of the way their atoms are bound and placed inside the crystal lattice.
Both the solids (diamond and graphite) differ essentially because of the covalent bound and the disposition of the atoms inside the crystal lattice: in the crystal of the diamond, carbon is placed along the four vertex of a tetrahedron and all the electron form bounds, otherwise, in the graphite the atoms are placed in layers of hexagonal rings and the elctrons do not form the same type of bound, but there is a couple of electrons able to form a weak bound perpendicularly to the layers of the reticulum.
This weak bound between the layers of the atoms, in that shape particularly easy to identifiy because of its hexagonal characteristic, justifies the extreme facility that makes the graphite break (think about the pencil lead, when you are writing the pencil lead leaves pieces of graphit on the sheet), otherwise the diamond is used for its abrasive propriety, because of its extreme hardness: to cut a diamond is required another diamond. The graphite can turn into a diamond under specific conditions of temperature and pressure, this transformation requires a process that occurs naturally inside the earth’s mantle, where those sizes reach extreme values.
When it is formed into the depths of our planet, the diamond appears on the earth’s crust because of the telluric movements that occur over the millennia. In nature, the pressures favourable for the formation of diamonds are 70.000 Kg/cm and the temperature of 2000°C, are found at a depth of 150 km or more near 2,5 billions old “cratons”.
So, it is the rarity of the diamond, its atomic structure that defines the preciousness and the high value in the global market.
