After the diamond, the stones that we associate, more than any other,  with the goldsmith's art, that we expect more than others to see set in a jewel and that automatically recall us the idea of ​​"preciousness" are, without any doubt, the ruby, the sapphire and emerald. It is these (always together with "his majesty" the diamond) that reign supreme in the windows of jewelery shops all over the world. It's because of that they are called "The big three". Their color often becomes synonymous of the color itself. In fact, in nature, in painting and in literature but also in our simple daily life we ​​speak of "ruby red", "sapphire blue" or "emerald green" when we want to underline the intensity of a sunset, the pure beauty of the sea or the vivid intensity of a meadow. Ruby and sapphire are respectively the red and blue variety of corundum, while emerald is the green variety of another mineral, beryl, whose blue and red varieties, we say just to digress, are the well-known aquamarine and the decidedly less note bixbite. Corundum is an allochromatic mineral (like beryl) which in simpler terms means that its color is due to external chemical elements. In this case, ruby ​​owes its color to the presence of chromium.

Each of the "big three" deserves a chapter on its own and we will begin with the ruby ​​(from the Latin rubrum), a stone that has always been precious and whose colour, especially at its highest degrees of tone and saturation, can be said to have of an almost magnetic attraction. Small curiosity. Now this is no longer the case but it was the male stone par excellence, a symbol of physical strength and royal dignity. In Mughal India, for example, it could be found set on the hilt or sheath of a sword, in the center of a maharaja's turban or sewn onto his robes but a ruby ​​was rarely seen on a ring or a necklace, on the finger or neck of a princess. Let's take a trip around the world. The most beautiful and valuable rubies came and partly still come from the state of Myanmar (formerly Burma) and exactly from the Mogok mine precisely where, not surprisingly, the writer J. Kessel set the beautiful book "The Valley of Rubies". ”. Beautiful, high quality rubies (although not up to the level of those of Mogok) currently come from the Tsavo area in Kenya. A fair quantity of rubies (but of medium quality) is instead extracted in Pakistan, precisely in the Hunza valley, on the border with Kashmir. Sometimes, although increasingly rarely, rubies of exceptional beauty are mined in Sri Lanka where the average quality is still good with stones that very often have a characteristic pink tendency. Nowadays most of the good quality and less included rubies come from Thailand although it must be said that the latter often have an excessive tendency towards purple. In India, where the average quality is also low, it is more frequent than elsewhere to come across the "star ruby", a ruby ​​with a marked asterism which is almost always cut "cabochon" in such a way as to bring out the characteristic six-pointed star as best as possible .

The main and distinctive aspects of the ruby ​​are above all its marked pleochroism or, in the gems, the presence of a secondary color; then the silk effect, when it exists, and the notable shine which can be further stimulated if it is placed under a normal incandescent lamp and finally, most importantly, by direct sunlight rich, as is known, in ultraviolet rays . These are the main characteristics that allow the expert, at first sight, to distinguish it from stones that could be confused with it such as some spinels with a particular shine which however do not have pleochroism as they are not birefringent, from some red garnets which however do not brighten under direct light or from rubellite (the red variety of tourmaline) which however only very rarely presents a red as lively as that of ruby. In the past the matter was more complicated. Until the end of the nineteenth century and well beyond, due to the gaps in the gemological technology of those times, the absence of an adequate codification of precious stones in general or even simply a more or less deliberate confusion of commercial terminology, traders with few scruples they took advantage of unwary buyers. A myriad of common pyrope, or red, garnets have been traded and marketed as genuine rubies under the exotic denomination of “Cape rubies.” Miles and thousands of rubellites, despite having a significantly lower hardness than that of corundum (7.5 compared to 9 on the Mohs scale), have suddenly risen in grade and obviously in cost, clinging to the unlikely definition of "Siberian ruby". And what can we say about the "Balascian ruby", in reality nothing more than a spinel, for a very long time equated with the ruby ​​and sold as such, practically as if it were the same stone and as evidenced by the now well-known story of the "ruby of black prince" placed on the British crown (right above the Cullinan II, one of the best known and largest existing diamonds) which has belonged to English sovereigns since the 14th century and which only in recent times was discovered to be nothing more than a simple spinel although very beautiful and of a considerable weight (but this was already known) of 170 carats. Its synthesis or the creation of ruby ​​in the laboratory deserves a separate discussion.

A vast topic which is common to all precious stones which we will discuss in one of the next blogs. As for the synthetic ruby ​​here we just say Auguste Verneuil. Not the first to deal with it, as there had already been other attempts previously, but the first, this occurred between the end of the 19th century and the beginning of the 20th century, to achieve notable commercial success. As can be easily imagined, this created great confusion in the market and the price of rubies dropped drastically and remained so for more than a decade. Today, thanks also to current gemological equipment, any reliable jeweler, often just with the help of a good microscope, can give you the certainty that a ruby ​​is natural or not. The exasperating search, since ancient times, for more or less faithful imitations of the ruby ​​is due to its high value which in turn derives to a large extent (we are obviously talking about quality rubies) from an extreme rarity that is difficult to find in other gems, including diamond. Today, more than ever, its value is constantly growing. For beautiful stones of three to five carats with a beautiful color and good transparency, usually of Burmese origin, its value is often equal if not higher than a diamond of equal characteristics. There is another important consideration to make closely linked to the value of rubies. It is not unlikely to see, in the windows of the most exclusive jewelers, sapphires, emeralds and even diamonds that easily exceed ten carats just as there are in large collections and museums, set on scepters and crowns, the same stones that well exceed one hundred carats, while on the contrary, throughout the world there are only a few dozen gem-quality rubies exceeding ten carats. As they say, you can count it on the fingers.

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