We study Semiprecious stones, Gems, Minerals
Gemstone raw materials - jewelry, jewelry and ornamental and ornamental stones used for the production of jewelry and art products of applied value. Gemstone raw materials sometimes include collectible decorative materials.
Gems (from Russian Sam and Tsvetnoy) are precious, semi-precious and semi-precious stones (minerals and rocks), which are used as jewelry and semi-precious raw materials. As a rule, transparent or translucent. The term gems has a historical and everyday character, it does not belong to scientific terminology and is not strict. At different times, in everyday speech and the speech of various specialists, it could also refer to translucent or opaque stones, or be used to categorize colored-colorless, cutting-decorative-decorative, precious-semi-precious stones. The term has been used in the Urals since the 18th century, it was mentioned by M. I. Pylyaev, but it was widely introduced into practice thanks to the works of A. E. Fersman. According to Fersman's classification, transparent stones are gems, regardless of their classification as precious or semi-precious; opaque minerals and rocks belong to the “colored stones”.
Gems, their physical and chemical properties
- Alexandrite - natural chrysoberyl and synthetic stones
- Diamonds and diamonds are the most advertised jewels.
- Pearls are the generous gifts of the tropical seas
- Emerald - dense green precious beryl
- Moonstone: adular, whiteite - transparent, white and blue stones
- Opal noble, black, fiery, cacholong
- Ruby - noble red corundum
- Sapphire - noble corundum of yellow and blue color
- Chrysolite, demantoid - green precious garnet
- Diamond cut and gemstone cut types
Gems and precious stones of Ukraine
- Agate is one of the most attractive gems of Ukraine
- Amazonite - green microcline, green stone of Scythian Amazons
- Beryl - actually Ukrainian beryl, emeralds and aquamarines
- Gagat - "black amber" of the ancients or "black amber"
- Hematite and Jespilit - Ukrainian Red Quartzite
- Gypsum, alabaster and anhydrite are popular semi-precious minerals.
- Petrified wood and fossil wood - the original gem
- Pearls, nacre and other petrified marine animals
- Crystal quartz - rhinestone, amethyst, citrine, morion
- Flint is a patterned and colored ornamental gem with a long history.
- Labrador - stone flower of Ukraine, colorful peacock stone
- Opal ungvovarit - green chloropal Carpathians and other opals of Ukraine
- Pyrophyllite or agalmatolit - the story from the Neolithic to the present day
- Written granite - ancient letters and hieroglyphs of nature in pegmatite
- Carnelian - the legendary stone, historical legends of cornelian
- Sodalite - a cornflower stone deserving more attention
- Brindle, cat and falcon eyes from Volyn and Krivoy Rog
- Topaz - the true beauty of Volyn land and the pride of Ukraine
- Tourmaline and its black variety of Sherl from Azov
- Fluorite - "ore flower", a beautiful and multicolored stone
- The Black Sea Route - the original Crimean green stone the color of the sea
- Yantar (burshtin) - a traditional subject of the Ukrainian craft
- Jasper rainbow - natural painting and a riot of colors in the stone
- Other original stones and minerals found and mined in Ukraine
The articles below, which describe the physicochemical properties of stones and minerals, are intended for more “advanced” stone lovers, and not for beginners. The materials below do not contain the magical and healing properties of stones and may present some difficulties for beginners.
Popular gems, represented in the CIS (former USSR)
- Diamond is the hardest and one of the most expensive minerals in the world.
- Alexandrite (chrysoberyl) - one of the rarest and most original stones
- Beryl (a group of beryls) - heliodores, emeralds, aquamarines, morganites
- Turquoise - the blue and green gem of the East
- Pomegranate (a group of garnets) - popular inexpensive gems
- Jadeite is a popular stone that was used in the Neolithic period.
- Pearls - the traditional and favorite jewelry of the Slavs
- Quartz (a group of quartz) is an extremely popular mineral in collections.
- Corundum (group of corundums) - colorless corundums, rubies and sapphires
- Lazurite - the blue stone of the high blue mountains of the Pamirs and Afghanistan
- Malachite - Ural malachite is considered the best in the world.
- Jade - the sacred green stone of the Chinese emperors
- Feldspars - Labrador, Moonstone, Sun Stone, Amazonite
- Rhodonite (Orlets) - a beautiful pink stone of the Urals, the stone of Russia
- Topaz - blue, yellow, wine and polychrome minerals
- Tourmaline - original gems of all colors and shades
- Fluorite is a valuable mineral used in industry
- Chrysolite - a magmatic mineral, transparent garnet olivine
- Spinel was relatively recently allocated to a separate class.
- Amber (fossil resin of ancient trees) - frozen time
- Jasper is an extraordinary mineral with the broadest color palette.
Catalog of green stones and minerals
Catalog of red and dark pink stones
|Cinnabar (poison)||Corals||Pyrop (garnet)||Ruby (corundum)|
Catalog of blue and dark blue stones
|Turquoise||Gawlit, caulite||Dumortierite||Lapis lazuli|
|Sapphire||Sodalite||Topaz||Celestine (poison + radiation)|
Native elements. Very few elements are found in nature in a free form as "native". The ease with which metals and non-metals come into conjunction with other elements, especially oxygen, causes their presence in the earth's crust almost exclusively in a bound form, as part of different compounds. Therefore, it is sometimes possible to extract an element using relatively simple operations and then use it in a technique; sometimes it requires a complicated and expensive process of isolating an element from compounds using a set of methods. The few elements found in nature in their native form eliminate the difficulties associated with separating them from other components (for example, as in the case of noble metals, including platinum), and from the negative environmental impacts that one has to face. when working with certain elements, whether metals or non-metals. A completely exceptional case is iron, which enters the earth's crust in its native form as part of meteorites.
Sulfides include sulfides (metal compounds and sulfur S) and other compounds related to them: selenides, tellurides, arsenides (toxic compounds with arsenic As), antimonides and bismuthides. These include oxygen-free compounds formed by the combination of various metals with sulfur, selenium, telur (having chemical properties of non-metals) and with semimetals - arsenic, antimony, and bismuth. Currently, there are about 400 mineral species belonging to this class. However, they are mostly found in insignificant quantities and are of purely scientific interest. But those described here are of economic importance. Various sulphides are an important and often the only source of elements of extreme practical value and necessary for industry. Non-ferrous metals such as copper, lead, zinc, mercury, molybdenum, silver, and many rare metals (tellurium, selenium, germanium, iridium, etc.) are mainly obtained by processing sulphides.
Halides (or halides) are chemical compounds formed by the combination of halogens and metals. In nature, the most common halogen is chlorine, followed by fluorine. Bromine and iodine are more rare. Chlorides and fluorides are represented by a number of minerals, while bromides and iodides in nature are few. Bromine is included only in one, rather rare mineral - bromargirite, and iodides are known three mineral species. Fluorides are found in hydrothermal veins (fluorite) or, much less often, in pegmatites (cryolite).
Chlorides are more abundant and include a number of fairly common minerals. They were formed as a result of evaporation of the waters of the ancient seas or salt lakes (halite - table salt, carnallite) and, unlike fluorite, are absent among veined minerals. Among the products of the activity of some volcanoes, it is also possible to find some chlorides, both relatively common (halite) and rarer species. A significant amount of chlorides is formed during the weathering of ore minerals under the influence of atmospheric factors. Among metals, silver (cerargrite), lead, mercury, and copper (atacamite) are most often associated with chlorine.
Oxides and hydroxides. Oxygen is an element that is very common in the crust of the earth. Therefore, it is present as a major component in most minerals. Most often it is simultaneously associated with two or more elements, one of which is a non-metal, such as calcium sulphate (CaSO4, which forms gypsum and anhydrite. From the chemical point of view, this substance is considered as a salt of sulfuric acid (H2S0J, and not as an oxide Oxides are those compounds (in our case, minerals) that were formed during the binding of oxygen with one of the elements, mainly metal (such as corundum - Al2O3), as well as with several elements, provided that these compounds cannot be considered typical salts . Many minerals, say, perovskite (CaTiO3) or spinel (MgAl2O4), are considered oxides in some classifications, and titanates and aluminates in others. Hydroxides differ from other minerals of the class under consideration by the presence of OH hydroxyl group in place of oxygen.
Spinel (oxides). The group of spinels includes oxides with the general formula X Y 2 O 4 , where X and Y are metals, divalent (magnesium, iron, zinc and manganese) and trivalent (aluminum, iron and chromium), respectively. The most different metals can unite in one mineral. In nature, pure compounds are very rare. Spinel crystallizes in a cubic system, twinning is very often observed. Many spinels are the primary products of magma crystallization and therefore are present in many intrusive rocks. They are not uncommon in metamorphic rocks. The most common spinels: spinel itself, magnetite, chromite, franklinite, ganite.
Carbonates. Among the numerous minerals that make up the lithosphere, carbonates play an important role from the point of view of mineralology, petrography and industrial development. They are part of many sedimentary, metamorphic and igneous rocks. Carbonates are the main components, firstly, limestones, consisting mainly of calcite (calcium carbonate); then dolomites, composed of calcium and magnesium carbonate; finally, crystalline marbles, primarily sedimentary, but transformed by metamorphic processes, as a result of which their initial structure changed during the complete recrystallization of calcium carbonate. Carbonates are widely used in industry. They are used as building materials, including finishing; as raw materials for ceramics and as refractories. Carbonates are also ores of many metals, including iron, magnesium, zinc, manganese, lead, barium, etc.
Sulfates are characterized by the presence of SO4 in the formula. Telluriums, chromates, molybdates, and tungstates are assigned to the class (only Te, Cr, Mo, and W are present at the site of S). As for their origin, it can be noted that some have a hydrothermal genesis or were formed during exhalations (steam-gas emissions) of volcanoes. Others are of sedimentary origin, mainly marine, and still others are secondary formations. Sulfates are extremely widespread in nature. Telluriums and chromates are extremely rare. Molybdates and tungstates, which are about fifteen, are relatively more common. Minerals of this group are not rock-forming. Exceptions are gypsum and anhydrite, which form a large, monomineral composition.
Phosphates . In this category, in addition to phosphates (minerals containing the PO4 group), arsenates and vanadates (minerals containing the AsO4 and VO4 groups are also described. There are transitional forms between these compounds, from phosphates to arsenates, from arsenates to vanadates, and, rarely, from vanadates to phosphates. In the earth's crust, primary phosphorus is present mainly in the composition of apatite, which is common in almost all igneous rocks, in pegmatite veins and in some ore deposits. The processes of weathering, dissolution and transfer provide for the accumulation of phosphorus Atoms in soils and seawater. Living organisms extract phosphorus from them, which is necessary for their existence. Accumulations of remains of organisms and their excrement are deposits of great industrial importance. Arsenates and vanadates are mainly secondary minerals formed in sulfide-rich deposits. mainly arsenic and cobalt.
Silicates . Most of the lithosphere consists of silicates - very common minerals both among igneous and metamorphic and sedimentary rocks. Their value is great not only from the mineralogical (including as ornamental, decorative and jewelry stones) and petrographic points of view, but also from the point of view of raw materials for various industries. The composition of silicates always includes silicon, combined with other elements, such as oxygen, aluminum, iron, manganese, magnesium, calcium, and many others. They give rise to many minerals, often very complex in composition, which can often be easily determined without even using modern, highly sophisticated research methods. It was already noted above that silicon is part of several different modifications of silica, represented by quartz, tridymite and cristobalite. They are considered in this book as oxides, but a number of authors attribute them to the class of silicates because of the great similarity of their structures with the structures of tectosilicates.
Structurally in the crystalline lattice of silicates, each Si ion of silicon is located in the center of the tetrahedron, on each of its four vertices there is an oxygen O2 ion. In the aggregate, the silica ion and the four oxygen ions surrounding it represent a radical, or a complex anion — the tetrahedral group SiO4 +. It is the main structural element of all silicates. Tetrahedra in the structure can be isolated - as in the case of non-silicates; but they can be combined in different ways, creating other complex radicals. The combination of tetrahedra serves as the basis for the classification given below. The connection of tetrahedra occurs with the help of a common oxygen ion for two neighboring tetrahedra. In a situation when all four oxygen ions in a tetrahedron are common to him and neighboring tetrahedra, there are no more free valences. Then no cation is able to adhere to the complex radical, unless one or more trivalent aluminum ions replace one or more tetravalent silicon ions, thus freeing up additional negative valence. Aluminum in silicates can play a dual role. If it is part of tetrahedra, that is, it is part of an anionic radical, we are dealing with aluminosilicate. If it acts as an extratrahedral cation, then it is aluminum silicate. If aluminum performs both of these roles simultaneously, then we are talking about aluminum aluminosilicate. In a complex crystal lattice of silicates, additional anions often unusual for it are present, which fulfill the task of compensating for free valencies. Often water is present, both as a hydroxyl and in molecular form. In the latter case, it fills the channels of the crystal lattice, but its links with the lattice are very weak.
According to the latest scientific ideas on the structure of silicates, they, in accordance with the method of grouping SiO4 tetrahedra, are divided into the following subclasses:
Nososilicates (orthosilicates) - silicates with isolated or independent tetrahedra.
Sorosilicates (dioorthosilicates) are silicates with isolated Si2O7 groups.
Cyclo-silicates (ring silicates) are silicates with tetrahedrons combined into triangular, quadrangular or hexagonal rings.
Inosilicates (chain silicates) - silicates with tetrahedrons joined in single or double chains.
Phyllosilicates (layered silicates) - silicates with tetrahedrons combined into layers.
Tectosilicates (frame silicates) - silicates with tetrahedrons connected in the form of three-dimensional structures.
Garnets (silicates) . A group of quite common in nature minerals, often with difficulty distinguishable from each other. Their generalized formula can be written as follows: X3Y2 (Si04) 3, where X means calcium, magnesium, ferrous iron and manganese; Y - aluminum, trivalent iron, chromium, titanium, zirconium and vanadium. Grenades crystallize in a cubic system, very often in the form of well-formed crystals, devoid of cleavage. Based on the presence of trivalent elements in the chemical composition, they can be divided into the following rows: aluminum-containing grenades (pyrope, almandine, spessartine, grossular); iron-containing grenades (Fe3 +) - calderite, andradite; chromium-containing garnets (uvarovite), garnets containing titanium, zirconium and vanadium (kimtseit, goldmanite).
Epidote (silicates) . Epidotes are very important minerals from the point of view of petrography: being common elements of igneous and metamorphic rocks, they form isomorphic series of mineral species, each of which indicates the genesis of the rock in which it is found. The two main epidotes are clinozoisitis and epidote proper. The first combines calcium and aluminum, in the second aluminum is partially replaced by iron. The group also includes piedmont and allanite, which are, respectively, manganese-bearing and cerium-containing epidotes. In addition, zoisite, which is a heteromorphic analogue of clinozoisite (it crystallizes in another syngony — rhombic instead of monoclinic) is also referred to as epidote. Here it is described as a supplement to this group.
Pyroxenes (silicates) . The group of pyroxenes includes a large number of minerals, between which there are isomorphic series. From the point of view of crystal structure, they are all monoclinic. The exception is a series of enstatite - hypersten, whose representatives belong to the rhombic syngony; This row is adjoined by another, with an identical chemical composition, but with a monoclinic syngony (a number of clinoenstatitis - clinohyperster). The remaining rows: diopside - hedenbergite; spodumene - jadeite - aegirine; diallag - augite - fasasi. Isomorphic substitutions in pyroxenes are carried out in different structural positions, and different elements may enter one and the same position, and identical elements may enter different positions.
Amphiboles (silicates) . Amphiboles, like pyroxenes (with which amphiboles have many common morphological and chemical features), belong to the subclass of inosilicates, but are distinguished by the presence of ribbons of SiO4 tetrahedra in the crystal lattice. Optical properties are varied, and the chemical composition is quite complex. In addition, they are more widely distributed and in greater quantities than pyroxenes. For amphiboles, the elongated-prismatic habit is characteristic; the cleavage that appears along the prism directions is perfect. As with pyroxenes, amphiboles have monoclinic (a number of cummingtonite, actinolite, hornblende and glaucophane) and rhombic (a series of anthophyllite) representatives.
Mica (silicates) . This group of filosilicates includes numerous and important minerals, which, from the point of view of chemical composition, can be defined as aluminum and alkali metal silicates, containing also magnesium, iron, hydroxyl group and fluorine. If the number of ions of aluminum, magnesium and iron is 2, these micas belong to the muscovite row (paragonite, muscovite, glauconite, celadonite, luxurious). If this number is 3, these mica belong to the biotite series (phlogopite, biotite, annite, lepidolite, cinnivaldite). Micas crystallize in a monoclinic system, usually in the form of elastic plates, of low specific weight, with pseudo-hexagonal or irregular outlines; they are characterized by perfect cleavage, according to which they are very easily separated, low hardness and various colors. In nature, mica is very common and abundant: they can be found as essential components in a variety of igneous and metamorphic, as well as sedimentary rocks.
Chlorites (silicates) . This numerous minerals belong to the group of filosilicates. They have direct analogies with micas, but differ from them in chemical composition. Chlorites are characterized by increased water content and complete or almost complete absence of alkalis. From a chemical point of view, they can be considered as silicates of aluminum, magnesium and iron, as a rule, without the admixture of alkali metals. They crystallize in the monoclinic system in the form of small irregular scales of pseudo-hexagonal outlines, with perfect cleavage, resembling cleavage of micas. Chlorite plates, unlike micas, are flexible but not elastic. Chlorites are often observed in the form of rather dense scaly aggregates, massive powder clusters, fine flaked grains and worm-like clusters of plates. For chlorites, which are widespread and abundant in nature, the green color of various shades is characteristic. Of chlorites considered pennin, clinochlor and kemmererit.
Feldspar (silicates) . Feldspars are the largest and most well-known group of minerals that are the most important rock-forming components of rocks. They take part in the formation of a variety of rocks - both igneous, including both intrusive and effusive, and crystalline schists and sedimentary rocks. From the point of view of chemical composition, they are considered as aluminosilicates of potassium, sodium, calcium and, more rarely, barium, also containing impurities of other elements, such as lithium, cesium, rubidium, magnesium, iron, titanium, etc. The most significant members of this family are the result of a combination The three main components are: potassium aluminosilicate, sodium aluminosilicate and calcium aluminosilicate. Adjacent to them is rare barium aluminosilicate, Celsian albite and anorthite are two extreme members of the isomorphic plagioclase series, which also includes oligoclase, andesine, labrador and bitovnite. Plagioclases crystallize in two versions, high-temperature and stable at low temperatures.
Feldspatoids (silicates) . Under this name a group of minerals that are very similar in chemical composition to feldspars is combined. It includes potassium, sodium, lithium and calcium aluminosilicates. The structure of their crystal lattice can include extraneous anions, such as SO4, C03 and OH, water molecules and such elements as fluorine, chlorine. Some researchers do not recognize the existence of this group, which nevertheless includes about twenty minerals, from petalite to lapis lazuli.
Zeolites (silicates) . Zeolites are mineral species that can be defined as aqueous aluminum silicates of several alkali metals (such as sodium and potassium) and several alkaline earth metals, such as calcium and barium, less commonly strontium and magnesium. They are distinguished from other silicates by the ability to increase in volume and boil when heated. This property was reflected in the name of zeolites (in Greek - "stone that boils"). It is associated with the behavior during heating of water entering the crystal lattice, but weakly associated with the crystal structure. Zeolites are minerals of secondary origin. They fill cracks in the rocks and voids in the main basalt-type eruptive rocks. Zeolites are also found in granite rock geodes, in the form of cracks filled with mineral in gneissic rocks and sometimes in some ore-bearing veins of hydrothermal origin.
Zeolites are usually not used in the jewelry industry, but the ever-increasing role of these formations in engineering and medicine makes them truly precious. It is not by chance that zeolites received the figurative name of the “philosopher’s stone of the 21st century”. Zeolites are a whole family of minerals (water-containing aluminosilicates), including the cations of potassium, sodium, calcium, and magnesium. Their world production and consumption in 2000 alone exceeded 20 million tons. The term "zeolite" is translated from the Greek as "boiling stone" and indicates the low melting point of this mineral. Since zeolites are a kind of "porous crystals", they are able to exchange ions with the environment. Their unique sorption properties are based on this effect. In medicine and the food industry, zeolites are used as food additives that can remove harmful metabolites from the body without affecting proteins and other macromolecules. Some zeolites bind and excrete harmful substances from the body, and supply it with trace elements necessary for normal physiological activity.
Organic matter . This group is represented by substances formed by organisms that lived in past geological epochs. They petrified over time (like amber) or were replaced by various minerals (like oiled wood). In this sense, it would be necessary to include here a wide variety of materials (including fossil coal). In the mineralogical systematization, however, only those that are classified as precious or semi-precious stones are considered.
Via jewelery.org.ua, geokniga.org, mmus.geology.pu.ru, mirkamney.moy.su, kristallov.net, webmineral.ru, geo.web.ru, catalogmineralov.ru, mindraw.web.ru, mining -enc.ru, wiki