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Opal: The stone of



Opal is a stone not necessarily considered a mineral, it is rather called a mineraloid, which belongs to a separate group from the periodic table of chemistry. According to various classifications, it has a similarity to the pieces of quartz that are extracted from deposits, but it is not considered a quartz either.

The most notable characteristic at the moment of having a specimen of these in your hands, is the shine that it provides and the splintering that it has, it also has different colors and are classified in different ways according to the components that these pieces may have hidden inside.


Professionals in the mining industry tend to still consider this gem a mineral despite the circumstances that state otherwise, but many times they have to cling to the historical content that each piece has on the inside and the chemistry that it manifests, so that on the one hand it is considered a mineraloid and on the other handit is considered a 100 percent genuine mineral.

Now, the point is that we can take advantage of it without affecting it physically or chemically. To the correct sense of the professional words that have been eradicated with studies and evidence to show that opal in general terms is not a real mineral, meaning that words are dictated by experts in the field being studied.

Whether or not Opal is a mineral, we can call it stone and this stone is composed of different types of chemical components that are stored inside it and are carefully studied.


The chemical characteristics that maintains a wide compression within the white, black or any other type of opal are quite similar, all the types are often composed of silica dioxide, a component that is mistaken with quartz because it also contains it in good quantities and other associated minerals, they both also possess them and the confusion are quite consecutive until it reaches the point of studying the objects in question.

Throughout the formation of the layers there are different components, one of them being the tiny lepispheres, formed by successive layers in the development of cristobalite and other chemical compounds with quite particular names to pronounce; both minerals mentioned in their inner chemical components belong to the classes of silicates.

The high coincidence with quartz may be thought to be very difficult to believe, but when it comes the time to analyze and see that they coincide with the composition of quartz and other details that confuses everyone it can be understood what really happens.

An important difference in the structure of the similar chemical components between opal and quartz is that cristobalite and tridymite differ significantly from their respective crystalline structures, both of which have different structures, and there is already a difference that helps to differentiate these rocky materials from each other.


The Opal that contains in its interior different colors like a rainbow is the result of very microscopic particles that have an extremely small diameter and each small piece has the ability to reflect the sun’s rays and because of that moment the colors are created.

What differentiates opal from other gems or minerals is that its color is not due to variations in pigmentation or external agents that are introduced to the premature development of the piece, and with the collision of the components it releases those pigmentations of different shades such as white, black, green and others.


The White, Fire and Black Opal are the three most outstanding types of opals on the market and many people feel almost an instantaneous attraction when they become aware that they are close to a small semi-mineral specimen. The deposits from which this type of natural material is extracted are found in faraway countries, often an Opal is an element that results in the fossilization of animals and plants that die.

In the past, the opals were extracted in ancient excavations, but over the years and generations, exploiting the same lands, they reached a dead end in the area and they had to migrate to countries far away from everything; but before moving thousands of kilos in machinery, they always carried out soil analyses to see how viable it was to migrate to the populated areas.


Currently the world market for opal prices (around ninety-eight percent) is being manipulated by various deposits in Australia.White, fire and black opal are the most valued by people, so anything with a black or white opal increases its value exponentially, therefore boosting the market for this product.

It is a very precious stone in jewelry and in combination with diamonds or other super luxurious objects, the final valuation of a product may end up being millions of dollars, and this valuation depends on many factors as usual. It is necessary to make evaluations of materials to know what we are building and what we are going to build them with. A black Opal sincerely catches the attention of even the person who does not know this stone.


The points to be evaluated for a good opal are the hardness and purity that it has in its naturally formed crystals and in relation to this quality point, the irradiation levels according to its capabilities.

Opals usually don’t have a colored notebook. first starts with a color and then the piece starts to be colored in other ways.  By taking samples, the color chart is shown under a pair of microscope lenses where you can better detail the colors and components that cause these different shades along the inside.