Un focus sull’affascinante mondo delle gemme e sulle tecniche di lavorazione delle pietre e dei metalli. Saper scegliere un gioiello significa anche capirne il valore attraverso la conoscenza dei materiali che lo compongono, per valutarne il valore e apprezzarne appieno la qualità.

What is a diamond?

The word diamond comes from the Greek adamas (αδάμας), which means indomitable, invincible. This translation finds its foundation in the peculiar “indomitability” of the mineral, since its extreme hardness (10: the maximum on the Mohs scale) makes it the hardest material in the world, impossible to scratch. Such is its hardness that it can only be indented, and consequently processed, by the diamond itself.

The reason for its extreme hardness is its crystalline structure. The chemical composition of the diamond is made up of carbon atoms neatly arranged in a tetrahedral shape. The solid that is formed in this way is structurally very resistant and this gives the diamond its known physical and chemical characteristics that make it an extremely rare mineral.

How diamonds are generated?

Huge forces are required to distribute and compress the atoms of carbon inside the tetrahedral structure. Very high pressures and temperatures must be present – extreme conditions that occur inside the Earth’s mantle at a depth of about 200km. It is difficult for man to reach such depths.

In fact, the deepest mines in the world only slightly exceed a few kilometers, such that the presence of diamonds at such a small depth would be more than surprising. In reality, these diamonds are literally extracted and transported to the surface during volcanic eruptions by a volcanic rock called kimberlite. The diamond amalgamates with kimberlite, thus rising from the earth’s mantle over a period of least 15 centuries and finally reaching the surface, where the diamond is finally extracted.

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The processing of stones

Generally speaking, the value of a gem is based on combination of a series of characteristics, also called ‘value factors’ or ‘evaluation parameters’. Like with all other gems, diamonds with certain qualities are more rare – and therefore more valuable – than diamonds that lack them. There is a systematic way to determine these factors, otherwise there would be no way to compare one diamond to another.

Evaluation parameters

There are four important factors to evaluate diamonds, known as “the four Cs”:

– Clarity

– Color

– Cut

– Carat weight

The four Cs describe the quality of a diamond’s appearance in very precise terms and have become part of an international language that all jewellery professionals use to describe and evaluate particular diamonds. Thanks to these parameters, it is possible to describe, catalog and evaluate individual diamonds, thus allowing professionals to regulate their movement in order to accurately reconstruct the entire chain of the diamond.