Fire opal is a mineral considered as a precious stone, with a very particular dimension for the Roman civilization. Its origin would come from the Sanskrit name “upala”, then was nicknamed Pandora or Empress, in honour of the fire opal called the “fire of Troy”, in homage to the gift received by Empress Josephine from Napoleon I. Fire opal stone has a history worth talking about. It has inspired a lot of writers, who have not hesitated to compare it to the volcano, in relation to its very specific shade. As a symbol of purification, the stone is also associated with fireworks and galaxies, with a special value for the Romans, who considered its hue as a gift from the gods, a very precious good with divine connotations. According to Greek mythology, fire opal has an immunizing power that delivers an energy that is symbolic of truth and purity, but also infused with hope.
According to different accounts in books related to Mexican civilization, the Aztec civilization regularly used fire opal stone to make various jewels and utensils, which were primordial during human sacrifices and special ceremonies. Its name is associated with the plumage of the hummingbird, a revered animal. The most famous stone in Mexican history is clearly the mineral that is exhibited in Chicago in the Gainger Field Museum. It is a fire opal stone, of more than 35 carats, associated with a brooch, symbol of the Aztec god. It is a remarkable piece among the different existing varieties symbolising the Aztec civilization.
Since time immemorial, many books and numerous volumes have been written on this stone, with its small chips that have never ceased to fascinate scientists and gemologists. Considered as an extremely rare gemstone, it is regularly subjected to numerous analyses to better understand its molecular and chemical composition. Even with modern technology, scientists are able to reproduce diamonds or rubies, it remains truly different for opals. Compared to what you may have read earlier, the stone is truly emblematic of Mexico, exploited by the Aztec civilization, just as jade is used in a great number of ceremonial artefacts and jewels.
Compared to other existing gems, fire opal stone cannot be considered as a crystal, because it does not have precise nuances. That’s what sets it apart from other gems, with a very particular chemical composition. This gives the stone a very different dimension, much appreciated by humans, who consider it as a high-quality stone. With a high content of H20, it is composed between 20 and 21% of this substance which will have a considerable importance, on the final aspect of the stone. When the stone is exposed to high temperature, there is a bleaching phenomenon that occurs naturally on the stone. Its shade therefore varies with a rate of hydration that will provide a very pleasant play of light. This is why Hydrophanes opals are free of iridescence once the dehydration process has taken place.
Nevertheless, unlike their peers, they are absolutely not considered as noble opals. This Mexican stone, symbolized by its fiery colour and offering an average of 22 carats, comes from a mine in the Magdalena region. Forming in rock anfractuosities, it comes to fill the various holes in the rock, which is, moreover, subjected to very high pressures. According to its mineralogical structure, but also to its chemical composition that can vary from one stone to another, this will invariably lead to a very important variety of light, symbolising purification in some cases. This is what makes this gem so rich in diversity and appearance. Among the other existing minerals, this one is more prized in the world of jewellery as its lustres and shapes have always attracted man. Ideal for making outstanding jewellery, fire opal stone from Mexico really deserves its reputation, with such a particular colour.
Opal’s colour and shape are defined through a network naturally structured by spheres of silica, ensuring a diffraction of light in relation to these internal compounds. These silica spheres play a truly essential role, creating discrete luminous flashes or a most pleasant variety of light. Although there are some exceptions concerning this stone, it is generally formed in a sedimentary environment, close to volcanic activity. This is the case for the Mexican and Australian deposits. It finally results from a secondary alteration, from the dissolution of chemical elements that gathered inside. In other words, this means that opal stone is the result of a dried soup in which different chemical compounds, linked to volcanic or sedimentary activity, have been mixed.
In order for the formation of fire opal stone to take place, certain criteria must obviously be taken into account and respected, such as the presence of porosities, a continuous alteration of the rock by water, an impermeable layer that will prevent water from escaping from the rock, followed by a gradual drying out, composed of a mixture of silica and water. Once these different substances are present, heat will be essential in this formation process, a first cooling to 170° thanks to the presence of volcanic activity, or a cooling around 45°, close to the tectonic movements of the plates, ensuring this time the formation of Australian opals.
The extraction of this noble opal occurs in the same manner as the extraction of any common opal. It must be freed from the gangue of the rock, either by extraction using sophisticated tools that risk damaging the stone, or by manual extraction. In some cases, a technique consists of using dynamite to crush as much rock as possible and then to go in search of the various light fragments by hand. This represents a functional alternative, but finding the right fire opal stones is a painstaking task in this case. For the time being, Mexico remains the second-largest producer of the stone, just behind Australia, capable of using more modern techniques.
Various archaeological researches have brought to light certain writings in books or tomes, allowing a better understanding of the different means used in more ancient civilizations to extract the stone.
Fire opal stone has always inspired man, like the famous character of Cateline in a world with magical animals, such as the winged lion in an isolated tribe of the Sajaras.
A great number of virtues are associated with this stone, including its power to bring back joy of life and increased enthusiasm.
Don’t hesitate to read the story of the winged lion and Cateline, and the adventures of the Sajaras tribe. It will bring you a glimpse into the fascination that fire opal stone has inspired.