The world of stone is boundless and fabulously interesting. Amethyst and agate, rock crystal and granite, malachite and pebbles on the shore have a story. Man has been using stone since time immemorial. At first, he served him as a tool. In the future, those amazing properties that this material possesses contributed to the fact that it began to play a huge role in the development of human culture.
Using a sharp stone, a primitive man cut through the carcass of the animal he had killed. People made spatulas, scrapers, and bowls from the same material. Taking flat fragments, they ground the grains, and made jewelry from shiny and colored stones. A little later, the scope of this material expanded. The stone began to be used in architecture and construction, in decorative art and sculpture, as well as in jewelry.
Today, without this material, a person cannot even imagine his life.
Stone and mineral - principles of distinction
As a rule, we consider these two words synonymous. In principle, a stone can be called a mineral, and vice versa. This will not be a blunder. However, these elements still have several significant differences by which they are distinguished and classified.
A mineral is a chemical substance of one kind or another, having a crystalline structure. Sometimes its composition may have slight differences with a similar structure. In such cases, varieties of minerals are distinguished by color or other features.
As for stone, this concept is broader. By it is meant either a mineral or a solid rock of natural origin.
To better understand the essence of the difference, it is necessary to take into account factors such as:
- The existence of rocks and minerals. In mineralogy, this classification of stones is considered basic. Its basis is the conclusion that minerals are substances with a homogeneous structure. Rocks or just stones in their composition, in contrast, are heterogeneous.
- Minerals are used in jewelry. Stones, as a rule, are used as a building material.
- Esoterics considers minerals as an object that has magical properties. The stones do not have them.
- Minerals are always more expensive. Their cost is sometimes thousands of times higher than the price of stones. Minerals are much less in nature, since in its pure form any substance is much less common than material with impurities. Minerals look prettier. However, the practical benefits of rocks or ordinary stones are much greater.
- Minerals are products of nature located directly in the soil. That is why rhinestones, shellby obtained in the laboratory, can not be attributed to this category. You can call them stones.
As a rule, minerals are homogeneous. The impurities present in the crystal are called inclusions or defects. Because of them, the price of the product is significantly reduced. The mineral, which we call stone, is best complemented by an adjective. For example, "precious."
Stone classification
What are the characteristics of these substances? It is worth noting that a single classification of stones does not exist. Jewelers divide them according to one characteristic, mineralogists and geologists according to others, and sellers are primarily interested in the value of the goods they offer.
The first attempt to arrange the stones was made by the mineralogy professor Kluge Gürich. Greater clarity on this issue was introduced in 1986 by Bauer. He divided gems into three categories - precious, ornamental, as well as organic origin. Rocks did not fall into this classification of stones. In turn, these categories are divided into orders. However, at present, as a rule, they use the classification of stones proposed by V. Ya. Kievlenko. It distinguishes groups such as:
- Jewelry stones. This category includes the most beautiful and expensive representatives, which, in turn, are divided into 4 orders. The first of them contains ruby and sapphire, emerald and diamond. The second includes black opal, non-blue sapphire, tadiite and alexandrite. The third order includes red tourmaline and moonstone, rosolite and topaz, aquamarine and fire, as well as white opal, spinel and demantoid. The fourth includes citrite and almandine, pyrope and chrysoplas, amethyst and chrysolite, turquoise and beryl, as well as artificial zircon and varieties of tourmaline.
- Jewelry and ornamental stones. They are also distributed in orders. In the first of them is rock crystal, hematite, blood and rauchtopaz. The second order includes colored chalcedony and agate, rhodonite and amazonite, cachonite and heliotrope, ionizing obsidan and rose quartz, labrador and common opal, spars and white-porite.
- Ornamental stones. Not only jewelry can be made from them. Often they serve as material for various interior items. These include jasper and onyx, ganite and fluorite, obsidan and colored marble.
Sometimes a simplified or household classification is used to group stones. She divides them into precious and semiprecious, as well as semiprecious or ornamental.
The first grade minerals include: sapphire and diamond, chrysoberyl and ruby, emerald and alixandrite, euclase, spinel and fallen. Among the gemstones are considered those that belong to the second grade. Among them: zircon and opal, almandine and blood amethyst, phenakite and demantoid, red tourmaline and beryl, aquamarine and topaz. If we consider the classification of precious stones by origin, it is worth noting that most of them are minerals. These are homogeneous natural chemical compounds that have a crystalline structure and a specific composition. The classification of precious stones includes about a hundred types of minerals from an impressive list of 4 thousand elements.
Semiprecious stones include: epidote and pomegranate, turquoise and diopase, variegated and green tourmaline, rock crystal (clear water), light amethyst and rauchtopaz, labrador, moonstone and sunstone, as well as chalcedony.
Among the gems, there are: lapis lazuli and jade, amazonite and bloodstone, varieties of jasper and spar, labrador, pink and smoky quartz, amber and jet, mother of pearl and coral. When considering the classification of ornamental stones, it becomes clear that their list includes natural volcanic glasses that are part of rocks.
Most of the minerals are formed in the earth. In its depths, this element crystallizes and acquires a stable arrangement of molecules, ions and atoms. Minerals often have a strict face shape. The lattice of crystals or their internal structure determines such properties as the type of fracture, density and hardness.
In turn, rocks are a product consisting of several parts merged together. Their structure and characteristics directly depend on the conditions of formation, including the temperature and depth of the rock.
In the classification of natural stones, based on their origin, three groups are distinguished. It is igneous, metamorphic and organic. Let's consider them in more detail.
Igneous origin
What distinguishes such stones from the rest? Translated from the Greek word "magma" means "liquid fire alloy" or "mess." This substance has a temperature reaching up to 1.5 thousand degrees Celsius. When cooling magma, minerals and various rocks are formed. If such a process is carried out at a considerable depth, then they are called plutonic, if on the surface of the earth - volcanic.
Magmas and lavas are different in their viscosity and chemical composition. It also has a direct impact on the further classification of minerals.
It is worth noting that the crystalline structures of the stone begin to form after cooling of the rocks, when post-magmatic processes occur. Gems begin to "grow" in the voids of the rocks, forming sapphires and emeralds, quartz and topaz, alexandrite and rubies. All these minerals are typical representatives of the post-magmatic type.
At low temperatures that occur near the surface of the earth, the formation of patterned opaque minerals occurs. Among them are agate and opal, chalcedony and malachite.
In the classification of stones and minerals of magmatic origin, diamond stands apart. Sometimes it is the same age as the Earth. Diamonds form under special conditions. Crystals begin to “grow” in the mantle, at a depth of more than 100 kilometers. An indispensable condition for this is the highest temperature and pressure. Diamonds are "delivered" to the earth's surface by the so-called kimberlite pipes.
Minerals and rocks can also have sedimentary origin. This is another rather lengthy process of their formation. Its basis is the external influence of water and the atmosphere. Under the influence of rivers and precipitation, rock transfers from the surface of the earth. In this case, the rock is washed and eroded.
Metamorphic origin
Consider the second group from the classification of stones. Translated from the Greek language, the word "metamorphosis" means "transformation" or "complete change." Physico-chemical conditions that form in the bowels of the earth, in particular pressure, temperature and gases, have a significant effect on the deep layers of the soil. Under the influence of various factors, the breeds completely change. This process is also influenced by magma and catalytic substances.
Scientists have identified certain types of metamorphism. Among them:
- Immersion. A similar process occurs due to an increase in pressure, as well as the circulation of water solutions.
- Heating.
- Hydration. With this process, rocks interact with aqueous solutions.
- Impact metamorphism caused by explosions and meteorites.
- Dislocation metamorphism occurring due to tectonic shifts.
Stones having this type of origin are marble and garnet, feldspar and quartzite.
Organic origin
The stones from this category are characterized by the fact that many thousands of years ago they were particles of wildlife, and after they “froze”.
A similar characteristic underlies the classification of ornamental stones by their origin. For instance:
- ammolite is part of the fossil of one of the layers of the shell;
- jet is a kind of black (hard) coal formed from particles of ancient plants;
- pearls are formed in the shell in the form of pearlescent layers that cover foreign bodies that have fallen into the mollusk;
- coral is a tree-like formation with a calcareous structure found in warm seas;
- amber is a petrified resin of trees that grew over 40 million years ago;
- bloody finger - shells of cephalopods of ancient mollusks of Belemnites that existed 165 million years ago.
Minerals used for jewelry
The classification of jewelry stones is quite diverse. These minerals are distinguished by value, by belonging to a particular group, etc. But one of the most important classifications of jewelry stones is their breakdown into types based on what the appearance of these minerals in the world is. This issue is very relevant when buying jewelry with an elegant insert. After all, acquiring a valuable and beautiful thing, each buyer would like to understand what the origin of the mineral is. This will help determine how justified the costs incurred.
All jewelry stones are divided into four types by origin. Among them:
- natural;
- imitation of natural;
- synthetic;
- ennobled.
Let us consider in more detail the types listed above that are included in the classification of stones used in jewelry, by their origin.
Natural
These minerals are formed in the bowels of the earth by themselves. Man only produces and processes such stones. Jewelers give these minerals a finished look, making them cut and polished.
The degree of processing for natural stones is very important. Upon overcoming a certain threshold, the mineral passes from the category of natural to ennobled.
Imitation of natural stones
Such materials are very often used to create jewelry of lower cost. Buy jewelry with inserts from imitation of natural stones is preferred by those people for whom it is very important to make only an impression on others. The fact of the unnatural origin of the stone does not bother them.
What materials are used to simulate? For this purpose, natural or artificial stones are used, which in their external characteristics are similar to the original. For example, turquoise is often replaced by pressed crumbs of natural origin. Sometimes, colored plastic is used to simulate this mineral. For gems, most often they take glass of the corresponding tone. Of course, imitation is easily distinguishable from the original in its structure, chemical composition, as well as physical properties.
Synthetic stones
The aerobatics of jewelry science is artificially grown mineral. This substance, which is fully or partially the creation of human hands. A similar type of origin is mentioned in the case of minerals included in the classification of semiprecious stones, as well as precious.
The applicable synthesis technologies have reached such perfection that the physical and chemical properties of natural minerals and their analogues are absolutely identical. Synthetic stone can not always be distinguished from natural. On the one hand, this is his big plus. However, for some buyers, the “soul” of a real mineral is important, many people believe in certain properties.
Refined stones
These are minerals whose properties have been significantly changed through various processes. For example, jewelers sometimes heat stones. This allows you to change their color. Sometimes minerals are processed with ultraviolet rays. The simplest example of refined stones is a diamond, in which a crack is filled with a special compound.
Knowing the classification of jewelry stones and the characteristics of properties that correspond to a particular group, one can easily determine the value of minerals. Of course, due to their uniqueness and rarity, the most expensive are natural ones, which have not been subjected to any human influences. Synthetic stones follow in value. Due to the significant costs of their production, they also have a high cost. But at the same time, in some cases, they win when compared with natural stone of low quality.
Mass of minerals
There is a classification of precious and semiprecious stones and their weight. What is its measurement? For gemstones, the unit mass is carat. It is equal to 1.5 grams. Sometimes such a unit is called "metric carat."
Natural pearls are measured in grains. This is a quarter carat. Japanese jewelers sometimes use such a unit of mass as Momme.
The smallest diamond samples are measured using a point. If the raw jewelry is raw, then its weight is indicated in grams. The same unit is used when weighing ornamental and semiprecious stones. European jewelers sometimes indicate the weight of such minerals in ounces.
Based on the classification of stones by size, their value is determined. However, most often this applies only to precious and semiprecious stones. The cost of a gem depends on its weight by only a third. The main component of the price for ornamental stones is the quality of the mineral, its transparency, color, as well as the skill of the cutter.
Stones in the kidneys
Stones can occur not only in terrestrial soil. Not all of them are the result of human creation. In medical practice, a special type of disease associated with the formation of salt stones is distinguished. The presence of kidney stones is indicated by lower back pain and colic, hematuria and pyuria. When diagnosing pathology, it is necessary to determine the type of formations. This will allow you to prescribe the most effective treatment.
What is the classification of kidney stones? These neoplasms are distinguished by the following:
- quantity (as a rule, single stones are identified by doctors);
- the place of localization - in the kidney, in the bladder or in the ureter;
- location in the kidney - bilateral or unilateral;
- form - round, spike, flat with faces or coral;
- size - ranging from the eye of a needle to the volume of a whole kidney.
Based on their origin, in the classification of coral stones, formations formed by an organic substance, as well as on an inorganic basis, are distinguished.
By their chemical composition, kidney stones are:
- oxalate, arising from an excess of oxalic acid salts in the body;
- phosphate, the development of which is promoted by calcium salts;
- urate, forming at elevated levels of uric acid salts;
- carbonate, originating from salts of carbonic acid;
- struvite, formed with an excess of ammonium phosphate.
Separate stones with organic origin. These are protein, cystine, cholesterol and xanthine stones.