The treasures of the stone belt
The treasures of the stone belt
The Urals is the planet’s unique geological province. Inimitable peculiarity, duration and complexity of geological development gave birth to its unique mineralogical diversity Academician A. Fersman wrote:
«There is no land in the world so abundant in natural resources…».
Mineralogical study of the Urals commenced in the second half of the 18th century. Rapid growth of mining and metallurgy gave a strong impetus to this process. Three centuries had passed since the beginning of the region’s industrial development, that resulted in many mineralogical discoveries, the majority of which were of the world’s significance, in 1766 the first in the Urals and in Russia new mineral crocoite (the initial name was «red Siberian lead ore») was discovered. This discovery was related with the name of Academician I. G. Leman (1700-1767). He published his researches in a booklet in Latin. Unfortunately Leman had not enough time to reveal the chemical nature of the opened mineral, he tragically died in 1767 during chemical trials with arsenic. Only three decades later L. N. Vokelen happened to separate a new chemical element – chrome – out of crocoite.
On the total, 87 minerals have been discovered within the years of a profound study of the Urals. Six new chemical elements separated out of them occupied their places in Mendeleyev periodic table: chrome found in crocoite of Beryozovsky deposit; ruthenium separated from native platinum; samarium, gadolinium and europium hidden in samarskite of Ilmen mountains; beryllium found in beryl.
The past millenium gave us about 4000 mineral kinds. The aggregate mineral fund of the Earth is near 6000 items. Approximately a quarter of all the known mineral kinds is kept in the Ural underground deposits.
The richness and diversity of the Ural minerals has always been attracting the attention of both scientists and stone-lovers. Visiting the Urals became one of the most significant events in a professional career of many of them. Gustav Rose described his visit to the Middle Urals and Ilmen mountains as follows: «I am happy to visit these beautiful places that charm any geologist and mineralogist, a great amount of numerous minerals is concentrated in a small area. Low hills and ranges covered with woods are in fact a natural museum displaying the most valuable rare minerals gathered by the nature itself». Many of them are named after Russian scientists, statesmen or the place of their discovery.
Gold is a magic metal with wonderful specifications, “the symbol of everything eternal”. D.N.Mamin-Sibiryak wrote: “The major part of ever mined gold has been utilized up to now, it changes just its owners and purpose, it passes through centuries… In all times it magically attracted mankind as it do it now and will do until our sinful people’s world is existing…”
Charming colour, almost unlimited malleability and ductility, resistance tuuxiUatiun undci ilic influcncc of air, water and fire promoted gold to the first place among all the metals, made it a perfect metal. Gold belongs to the number of super-rare elements, its average content in the earth-crust is 0.0000004 percent, which is in hundreds of thousands times lesser than the content of many rare elements.
The traces of the first gold mines in the Urals go back to the IIIrcl millenium B.C. in historical aspect the Urals is the first Russian gold-bearing province. In 1745 the first in Russia Beryozovsk native gold deposit was discovered there.
In America, Australia, Africa gold fields were firstly found and only then native gold followed.
In Russia the situation was entirely opposite. Only a half of a century later, in 1814 the first gold fields were discovered in Beryozovsk deposit.
From 1745 to 1917,704.2 ions of gold were mined in the Urals, among them 559.2 tons from the fields, in the Soviet period gold output amounted to 1,200 tons.
A typical trend of the Ural fields is presence of nuggets of gold. ‘Tlie Tashkutarganka river in the basin of the Miass river had merited fame for its nuggets.
On October 26.1842 the “Great triangle” nugget was found there, its weight was 36,040 g.
The number of nuggets weighing from 1 zolotnik (4.6 g) Ю ;i pound (409 g) amounted to thousands. Such a concentration of nuggets in the area of merely 8.5 km long and 100-600 m wide is absolutely unique in the story of the world gold industry.
Gold occupies the 80th place as regards the extent to which it is spread in the earth-crust, however, as regards the number of minerals in which it occurs as a kind-building element it essentially surpasses its neighbours in the Mendeleyev table. Today 25 such gold-bearing minerals are known. Ten of them has been revealed in the Urals.
According to Academician A. N. Zavaritsky standpoint put forward in 1924, “the most remarkable peculiarity of the Ural metal deposits is the platinum deposits. These are the largest concentrations of the rare-earth element very significant for our cultural progress”.
Platinum was found in the Urals in gold-bearing fields of Verkh-Neivinsk district.
Hie first platinum proper fields were discovered in 1824 on the Orulikha river in (ioroblagodatsky mining district. Isovsky and Nizhny Tagil districts proved to be the most productive in its mining.
The remarkable trend of Nizhny Tagil fields was an abundance of large nuggets of platinum. Only in 1827—1829 3,334 nuggets weighing from 4 g to 1.5 kg were extracted from the fields at (he Solovyova mountain in Alexandrov ravine. Liter a nugget weighing 8,335 g was found there. The largest of all the known platinum nuggets weighing 9.624 5 g was extracted in theSvrkov fields in 1844.
In 1892 А. A. lnostrantscv revealed acc umulacions of chromite with platinum inclusions in the native rock of the Solovyova mountain.
The deposit was named after gold-prospector Serebry akov.
The year 1892 entered the history as the year of discovery of the first native platinum deposit not only in the Urals but in Russia in general.
The exploitation of the Ural gold >laiinum and platinum fields resulted in discovery of many new minerals, among them osmic iridium (given typically Ural names ‘Ncvianskitc’ and ‘Sysertskite’), tantalum carbide, niobium carbide and others, in 1844 Professor of Kazan University K. Klaus separated a new chemical element – ruthenium – out of the Ural platinum.
Today platinum is not only a precious metal used in jewelry, but also it is one of the most vitally important for the scientific-technical progress inputs. Professor О. E. Zvyagintsev, one of the founders of the Soviet platinum industry compared its significance with the significance of salt in food- making: Many today branches of industry; science and technology can not exist without platinum.
Silver is a precious metal the story of which like that of gold goes hack to ancient times. It is widely utilized.
It Is often arranged in of thin plates and small leaves, different wire-like shapes are also frequent. Native silver mainly looks like wrong in shape grains and lumps, very rare crystals. The surface of silver samples practically does not retain its natural colour. As a rule, the colour changes under the influence of oxidation and another chcmical processes into yellow, brow n and even black.
Today native silver is very rare in the Urals. However, in the 19th and 20th centuries when the zones of oxidation of copper and polymetallic deposits were exploited, silver was regularly found. The first description of the Ural silver was given by I. F. Hermann. These were the leaves of native silver found in Bcryozovsky mine in 1794. Presence of native silver in the so-called “Iron hat” in Turyinsky mines was witnessed by G. Rose (1837),
Yc. S. Fyodorov and V. V. Nikitin (1901). According to the data supplied by G. E. Shchurxmky (1841) native silver in form of leaves, hairs and a thin film was met also it» Gorno- Ana tolyvvsky polymetallic deposit. There arc also another eases of native silver found in the Middle Urals in lllagodainy mines, in the zone of oxidation
pyrites deposit as well as in KochkatsKy district in the Southern Urals Discovery of silver in Satbaiskv deposit dates &om 196-1 In 1967 it was follmvcd by a new large finding: a t vity «да wivd in tlK- wtHI of an exploited quarty About 100 kg of silver were extracted out of ihH cavity In 1992 at ilie same place about 300 kg of silver ami a vciy ruliai MilfuK’ niintr.ilogic.ll complex weie discovered in a new cavity: The basic shape of a native silver is wire-like (Ihrcad- shajK’il) crystals siivteheil along an axle. Thin wire-like silver prevail:*, live length of ‘-operate samples reaches 10-15 cm. tlK- wiic is intikatc-ly aincd and twisted into rings and spirals. Loose, spongy samples are also met. The silver of Sarbai by an exclusive chemical purity; ov er W)9 percent. .Vs a rule, native silver isaccom panted with other rare In the Urals and Russia minerals
Diamond was given its name for its extreme hardness. There is nothing comparable with it in hardness and, in this light, diamond may be treated as an eternal mineral. Moreover, diamond is the most beautiful of all the precious minerals, it develops characteristic marvelous optical effects.
The first llral diamond was found by 14-year old Pavel Popov on July 5, 1829 in the area of Krestovozdvizhensky fields. Two more crystals were found at the same place several days later. One of them has been kept in the museum of Berlin University up to this day.
Its detailed description was made by G. Rose: ‘its facet is slightly broken in the direction of a short diagonal, and, as it cleared out later, the majority of the Ural diamonds belong to the so-called Brasilian type”. Before 1922 slightly more than 200 crystals had been found in Bisersky district in Krestovozdvizhensky fields, the majority of them were small, the largest one being about 2.5 carats. All of them were round in shape and transparent, sometimes shot with yellow.
In 1893 P. V. Yeremeyev dcscribcd two diamond crystals from the gold-bearing fields in the Southern Urals. A sample found in the vicinity of the settlement of Kochkai was an isometricallv developed crystal weighing about 1 carat.
In 1895 during the exploration of a mineral deposit of the Polozhikha river located in the eastern slope of the Middle Urals a diamond weighting 1 i/8 carat was found.
In the middle of the 20th century presence of diamonds was witnessed in the fields of Kolvo-Vishcra district of the Northern Urals. Industrial extraction commenced in 1955. Today it is undertaken by a jointstock company “Uralalmaz”. This company supplies about 1 percent of the aggregate Russian output of diamonds. The diamonds of Vishera are characterized by an anomalous (up to 80 percent) ratio of their jewelry sorts.
Today diamond is found in the Urals in different in age and genesis fields as well as in kind of single findings.
Ruby has always been a gem highly appreciated by all the nations for its hardness as well as for its wonderful charming, very- durable to nearly eternal colours. In ancient Russia it was called “red yakhont”.
Ruby, sapphire, starry ruby arc gems of one and the same mineral class of corundum.
For a long time the varieties of corundum were described as separate minerals. As late as 1805 Gajuis united them into a single mineral category, though the identity of all these varieties had been well-known long before.
In the Urals corundum was known long since. It is widely spread along the whole of the eastern slope of the Urals. In Murzinka-Adui mineral line ruby was known since 1738.
The first discoveries were made by К Babin. Rock crystal and red, blue and green stones were mined in the Kornilov ravine.
In 1962 Kh. G. Shlyakhov for the first time discovered red corundum in the Rai-Iz massif. The corundum crystals arc barrel-shaped. Of a particular interest are the samples in which the crystals of ruby colour stand against the background of a dark mass. The crystals often develop the effect of asterism.
The average dimensions of the crystals arc 1-3 cm, the largest one is 12 cm in diameter and 20 cm long.
A crystal cm high and 8.5 cm in diameter is exhibited in the Ural Geological Museum. This is one of the largest minerals lately discovered in the deposit.
Today the attraction of gem-lovers, collect ioncrs and mineralogists is focused on a new ruby mineralization discovered in marbled limestone in the Southern Urals, in the Kochkarskaya area. Mineralized zones resemble lenses in shape. Ruby’s colours are crimson-red, carmine-red, red-violet. The weight of separate not-defective samples docs not exceed 1 carat, however, some crystals do reach 2-3 g. Apart from ruby spinel is also met. Such a mineralization has been revealed in a marble deposit of Murzinka-Adui, Dzhabyk- Karagai and Sunduxky metamorphic complexes.
Sapphire is a luxurious and hard mineral of extra-class. Like ruby it is referred to the category’ of corundum.
In ancient Russia it was called ‘azure ruby’. The mineral’s colour was precisely described by A. Kuprin:”… some of them resemble in colour cornflowers in wheat, another ones resemble the autumn sky, some of them resemble the sea in sunny weather”.
Asterism is typical of sapphire: a light star with 3,6 or 12 rays is exactly shaped on a polished stone. Thin needle-like inclusions of rutile develop this optical effect.
In the Urals native deposits of a sapphire-like corundum occur in Ilmensky and Vishnyovy mountains. Bright-blue sapphirelike corundum is genetically related with pegmatites. Small mountings made of it arc not inferior to Oriental sapphire neither in colour, nor in any other aspect.
The earliest evidence of sapphire extracting in the Middle Urals comes from the 18th century. In 1858 a girl of the village of Kornilovaya found sapphire there. It was faceted and gifted to the Tsar. According to the data supplied by Л. E. Fersman, the corundum of the Polozhikha river, deep- blue, blue-red, violet-blue, red, dark blue up to black in colour, from 0.5 carat and larger were not inferior to Oriental minerals in their purity.
In 1904 mineralogist V. I. Vorobyov noted that “ruby, sapphire and quartz may be found all around the rivers and ravines in the vicinity of Chcrcmisskaya and Koltashi and even in a clay in the field. But their quality is low. Only the samples of Koltashi are of a fine quality”.
Beryl is one of the most desired mineral in any collection. Its effective crystals are harmonically combined with a wonderful mineralogical diversity.
Beryl is a circular silicate of aluminium and beryllium, but, as a rule, its samples contain insignificant admixtures which turn the colourless mineral into beautifully coloured varieties. Their colour (with the exception for emerald) is caused by ions of divalent and trivalent iron occupying different positions in the mineral’s structure on which the wide spectrum of colours and shades depends: green emerald, light-blue aqua m a ri ne, goldcn-yel low heliodor, pink vorobievite and morganite. In nature beryl is met, as a rule, in form of crystals and no matter their colour is all its modifications have identical appearance.
The Ural beryl served as the input in which L I. Vokelen discovered a new chemical element, glicinium (beryllium) on February 14, 1798. The multi-volume atlas of cry stals composed by V. Goldshcmidt (1853-1933) contains 160 drawings of beryl crystals, 50 of them being of the Ural origin. The majority of crystals were studied by N. I. Koksharov. He had revealed 21 crystallographic forms of beryl. On the total, there arc about 80 simple forms of bery l crystals.
Single crystals are typical of beryl, junctions arc quite rare. The ordinary ore beryl from the Emerald fields have not transparent crystals coloured in yellow, yellow-white, greenish, dark-green in colour fascinating with an exact crystal shape. Apart from attractive colour beryl is also distinguished by the dimensions of crystals.
Many samples were found in the Semenovskaya fields of the Adui deposit.
In 1889-1890 more than 35 poods of greenish-yellow beryl were mined there. These were large-size (up to 20 cm), exclusively pure cry stals homogeneous in shade and simple in shape.
A marvelous collection of bery l is exhibited in the Ural Geological Museum. It contains fascinating aquamarines of Adui, the most beautiful samples of hcliodor of the “Kazennitsa” deposit and the pride of the l.’ral gems, emerald.
Emerald is referred to the most ancient and valuable gems. Underground mines were discovered in Egypt where emerald had been extracted as early as two thousand years B.C. Even at that time it was one of the most expensive minerals.
The story of the Ural emerald also goes back to the far past. Thus, it may be supposed that the Scythian emerald mentioned by Pliny the Elder is just of the Ural origin. However, the true story’ of the Russian emerald began far later.
On January 23,1831 a peasant of Belov arsky uezd M. S. Kozhevnikov found green crystals on the Tokovaya river.
The Ural emerald deposits are concentrated in a compact belt (the Ural Emerald fields) stretched in a meridian direction for 25 km, and in width for 2 km. It is comprised of such well-known deposits as Malyshevskoye (Mariinskoye), Pervomaiskoye (Troitsky fields), Sverdlovskoye (Sretenskoye), Cheremshanskoye and others. From 1831 to 1986 more than 2,378 thousand carats of gems and almost 50 tons of emerald raw were extracted there.
Emerald is the most beautiful and beloved in all the times gem. Its main merit is related with its colour. The aforecited Pliny the Elder wrote excitedly: “There is no a more fascinating colour in the world. Even green grass or leafage make us charmed, but emerald is far more charming, since there are no more so green articles in nature as it is. Moreover, looking at gems an eye is admiring but not tired, a sight of emerald returns sharpness even to an eye tired of another articles. Apart from it, longer you are looking at emerald larger it becomes as if it paints the air around it, neither sun, nor shadow, not lamps can change it…”
Emerald is a bright-green chrome-containing variety of beryl. Apart from the chrome- absorbing bands, light-absorbing bands are often typical of natural emerald. This is explained by an addition of ions of divalent and trivalent iron. The Ural emerald has the largest content of iron, which causes its slightly yellow shade in contrast to Columbian emerald that is pure green in colour. Entirely transparent emerald is rare in the Urals. The majority of samples arc darkened to a certain extent. The following famous samples of emerald should be mentioned: “Kochubeyevsky” weigh i ng 11,130 karats, “Kommerchesky” – 12,900 karats, “Shakhtyorskaya slava” – 3,275 karats,
“President” – 5,860 karats.
All the crystals of emerald are unique, none of them are similar. A just description of this precious stone was given by A. I. Kuprin: “…it is green, pure, jolly and tender as a spring grass, when you are looking at it for a long time the heart gets light”.
The Urals Geological Museum posesses huge collection of emeralds. There are large crystals in black phlogopite metosomatisms, phlogopite – guartz – plagioclase pegmatites, as well as single crystals.
The characterisic features of Ural emeralds are their heterogeneous green colouring and small inclusions of dark mica. Pure bright-green crystals are very rare. Usually the emeralds are found together with alexandrite, phenakite and topaz.
Aquamarine is a blue or greenish-blue variety of beryl.
It may be treated as a brother of the acknowledged king of minerals, emerald. The crystal structures and chemical compositions of both minerals arc identical. The only difference is the admixture of chrome and sometimes vanadium that makes the unique colour of emerald. Aquamarine’s colour is a result of a small admixture of divalent iron. Nevertheless, it is just the colour that makes aquamarine fascinating. It can change its colour looking sometimes grey-blue like an autumn nasty day, sometimes it becomes azure like a spring clear sky; sometimes it is blue with a charming light-green shade like coastal waters of south seas in a sunny weather.
The colour had predetermined the mineral’s name: in Latin ‘aqua’ means water, ‘mare’ – the sea.
Aquamarine is one of the mostly wide-spread gems in the Urals. In the 19th century it was mined in a great amount and sometimes in large crystals in Murzinka and Adui area in the Middle Urals, in Ilmen mountains and Kochkarsky district in the Southern Urals.
Sometimes beryl crystals of aquamarine colours reached considerable dimensions.
A crystal of aquamarine from the Middle Urals about half a meter long is displayed in the Mining Museum of Sankt-Pctcrsburg Mining institute. Samples of extraordinary charming aquamarine were found in the vicinity of the settlement of Murzinka, where it is associated with black tourmaline, topaz and amethyst.
The very notion of “heliodor” has not had simple treatments in gemological literature. Some scholars all the varieties of beryl, from yellow like a straw to dark orange in colour refer to this category. Another scholars prefer to divide such beryl varieties into proper heliodor type with apparent orange shades and the so-called yellow- colourcd “golden beryl”.
Heliodor is a light greenish- yellow beryl discovered in 1910 in the area of today Namibia, there it was given its name.
In Greek heliodor means “the gift of the sun”.
The colour of yellow and greenish-yellow beryl variety is caused by ion of trivalcnt iron that substitutes for beryllium in beryl-oxygenic tetrahedrons.
A sharply impressed dichroism is typical of intensive yellow and orange beryl varieties. Their colour is related with substitution of aluminum by iron. The heliodor colour completely fades away in the process of heating crystals to the temperature of 700 degrees К in the air or in hydrogenous atmosphere.
In the first case heliodor becomes colourless, while in the second case it acquires blue or dark blue shade.
Golden (yellow like a straw) varieties of beryl are widely spread in theJJral pegmatites, and even do dominate in some pegmatite mines of the Southern Urals. However, everywhere they are closely related with ordinary yellow-green beryl. Orange colour of beryl crystals is rare.
The most valuable crystal of yellow like a straw beryl is kept in the Mining Museum of Sankt-Petersburg Mining Institute. It was gifted to the museum by Emperor Nickolai I. The crystal has a shape of a hexahedral prism with roughness and hollows. It was found on November 19, 1828 in 3 verstas from the village of Alabashki, in the Startseva pit.
Attractive rare samples of heliodor crystals were found in the pegmatites of Svetlinsky deposit in the Southern Urals.
The largest crystal of heliodor was found in 1967. its dimensions arc 4.2 cm long, 0.9 cm in diameter. Only a half of it adjaccnt its head was transparent. Just here in the fields of Vostochny ravine a heliodor crystal of about 6 cm long and 1.2 cm in diameter was found.
Alexandrite is a variety of chrysoberyl with unique optic specifications.
Chrysoberyl was confirmed as a new mineral by A. G. Verner in 1790; hitherto for a long time it had been treated as chrysolitc, mineral of olivinum group.The very name “chrysoberyl” is of an ancient origin, as early as in times of Pliny the Elder golden beryl was called so. The earliest evidence of the Ural chrysoberyl is supplied by Professor D. I. Sokolov in 1832: “Scientist of Emperor’s Court L A. Perovsky made one more remarkable discovery in the rich Urals. During his visit to the Ural Emerald fields he found chrisoberyl, its cry stal being of considerable dimensions”.
In 1862 Academician N. I. Koksharov gave the following description of that historical moment: “…in those days (April 17, 1834), when Russia celebrated today Emperor Alexander IPs coming of age, chrisoberyl was discovered in the Urals, it essentially differed from all the other coloured varieties of chrysoberyl.
The unique characteristics of the mineral had promoted it soon to the first places among richest minerals. Famous mineralogist N. Nordenscheld proposed to name the mineral alexandrite in honour of His Majesty”.
Chrysoberyl found in the Emerald fields in contrast to the other samples was distinguished by a strong dichroism, the so-called “alexandrite effect”. Under the impact of dichroism the colour of a transparent crystal or faceted mountings of alexandrite is dark-green to nearly emerald in day time and violet like amethyst in the evening artificial lightening.
The most remarkable samples of alexandrite were found in Krasnobolotny fields, in 1832 a unique lump of alexandrite consisting of 22 crystals was extracted. Its weight was 5.38 kg.
The Ural Emerald fields up to this day remain to be the only in the world native deposit of the most beautiful alexandrite and until the 80s of the 19th century it was the only in the world deposit of this mineral in general, biter alexandrite was discovered in the fields of the island of Ceylon and in the pegmatite veins in Brasilia.
Demantoid is a Ural gem, a fascinating variety of andradite – a mineral of garnet group. This rare and valuable mineral is characterized by a strong diamond brightness and golden- green colour. Some demantoids have yellow shade and are not in great demand. The diamond brightness and strong dispersion predetermined the mineral’s name (in Dutch “demantoid” means “diamond”). Its colour is caused by an isomorphic admixture of trivalent chrome. The crystals’ size is 1-5 mm.
The first discoveries of demantoid were made in 1868 by N. G. Nordcnschcld in the platinum fields of the Bobrovka river (a tribute of the Tagil river). They were discribed by P. V, Yeremeyev in 1871.
In 1874 the world-wide famous Sysert deposit of demantoid was discovered.
It was referred to the fields of the Bobrovka river of Polevskoi district. The samples of demantoid found there arc characterized by an extraordinary beauty and dimensions.
At the end of the 20th century Poldncvskoye and Novo- Karkodinskoye native deposits of demantoid were discovered.
Demantoid is lain in form of round lentil-shaped, oval grains. It often is arranged in grain-like accumulations, reaching in diameter 7 cm.
The dimensions of grains and crystals fluctuate from 0.5-1 mm to 608 mm. Dcmantoid’s colour is greenish- yellow, brown-green, yellow- green, bright-green with a yellow shade to nearly bright dark-green without yellow shades.
Topaz is not a rare mineral. There are rocks where topaz plays the role of a rock-building mineral. Sometimes these are essentially changed granitic rock. There is an evidence of topaz-containing vein rocks in Mongolia.
The evidence of topaz found in the Urals in form of well-built crystals of different size (initially under the name of “heavy weighing”) comes from early 18th century.
Academician N. I. Koksharov described topaz as follows: “Dimensions, perfection of crystallization and transparence of Russian topaz makes it the most beautiful of all the most varieties of topaz”. A. E. Fersman made far more emotional description: “Russia may be proud of its topaz, beauty of colours, purity of water and dimensions of its crystals has made them leaders among all the varieties of topaz occurring all over the world”.
In the Urals the most famous deposits are located in the vicinity of the village of Murzinka. Thus, the Mogol deposit has been known from the middle of the 18th century and had merited the fame of the source of rare blue topaz and fantastically beautiful lumps with topaz and heliodor.
In 1982-1986 ideally facetted crystals weighing 5.7 and 13 kg and the unique “Pobeda” (“Victory”) lump consisting of 27 crystals of the aggregate weight of 43 kg were extracted. Topaz is usually accompanied by tourmaline, citrine, beryl and some other minerals. There arc no analogues in the world to the Mogol deposit.
Marvelous crystals of topaz were extracted in Ilmensky mountains. They also are found exclusively in the veins of granite pegmatites. In late 18th century Cossack Prutov discovered colourless or slightly blue topazes, the pride of the Southern Urals. Exclusively rare exotic varieties of topaz lays in the fields of the Sanarka and Kamenka rivers, within the bounds of Andreye-Yulyevsky mine. Their colour changes from pale-pink to rich crimson and even pink-violet.
The dimensions arc 2-3 cm with an exactly shaped rhombic section. In the second half of the 20th century blue topazes were extracted from granitic pegmatites of Svetlinsky fields in the Southern Urals.
In 1804 the great citizen of France R. J. Gajuis said about tourmaline: “It is well-known that the substances named ‘schorl’ arc very diversified.
It seems like the scientists agreed to give this name to all the minerals that arc difficult to be placed
in the systematization”. Today the name of “tourmaline” is given to a group of minerals each of them having a very complicated composition but all of them being united by an identical constitution.
Minerals of the tourmaline group are complcx crystalline silicates containing boron united by a common inner structure. Today the group of tourmaline is comprised of almost 10 independent mineral varieties. Individual characteristics and to a certain extent the conditions of their occurring in the earth are determined by the proportion of such chemical elements as potassium, sodium, calcium, lithium, magnesium, manganese, iron, aluminum, chrome, zinc and so on.
The identity of composition determines also the identity of morphological and partially physical attributes; the crystals, hardness, brightness and density of all the varieties of tourmaline are close. Remarkable is the range of colours. Earlier some samples of the tourmaline group differed in colour: akroite was colourless, white; rubellite – pink, crimson-red; indigolite – blue; verdelite – green; schorl – black. The crystal’s colour is often heterogeneous. The varieties of tourmaline also differ in the rate of spreading in nature. For instance, schorl with a high ferro-content, black in colour is a widely spread variety, whereas albaite, liddicoatite though having jewelry’ characteristics are rare-earth minerals.
Of a particular value are the crimson-red tourmalines of Sarapulka; red, blue and green ones of Lipovka. Large crystals of tourmaline from dark-green to nearly black colour were found in Nizhne-Isetsk district.
In the area of Murzinka beautiful crystals of cherry-pink tourmaline were found. Their transparence and beauty of shade had no analogues in the world. Rare brown-red varieties of tourmaline originate from the well-known Mor mine in the vicinity of Shaitanka.
Phenakite is a mineral found in the Urals for the first time in the world. It was discovered by Ya. V. Kokovin in the emerald fields of the Tokovaya river in 1831 and initially it was named “kokovite”. Ya. V. Kokovin submitted the samples of phenakite to L Pcrovsky, who passed them to N. Nordenscheld for investigation. “The mineral was sent to me from Petersburg by the permission of Vicc- President Pcrovsky together with another Ural minerals. – wrote N. Nordenscheld. – Though the mineral was sent to me as quartz and b awfully identical with it, the peculiarities of its crystals made me thoroughly investigate it.
The trials in front of a blow pipe soon made me confirmed that the mentioned mineral was not quartz, which was further on proved by another analysis”.
N. Nordenscheld called the mineral phenakite (after the Greek “phenax” – a liar).
Despite being quite a widespread mineral for beryl deposits, phenakite very rare constitutes large crystals valuable for jewelry. Phenakite crystals arc isometric, rhombic or look like a short prism. ‘Hie crystals have up to 56 facets. One of the largest crystals was found in Malyshevskoye deposit in 1991. Its dimensions arc 7 x 12 x 13 cm. The crystal of “pure water’ had a deep smoky colour.
Phcnakite is colourless, however crystals of pinky-red colour sometimes were found in the Emerald fields. Phenakite’s colour is not durable, N. I. Koksharov seems to be the first to focus on this very peculiarity of the mineral.
He reported of this in a small articles in the Notes of mineralogical society (1869): “In 1867 Cabinet of His Majesty sent a beautiful, transparent and polished sample of phenakite (about 2.2 cm in diameter) to the Paris exhibition. This phcnakite had quite a deep colour before sending to Paris (like a colour of Madeira with a pinky shade), liuvvcvci being displayed for about two months it had entirely lost its colour and turned to an entirely colourless stone”.
In 1921 A. E. Fcrsman wrote: “In Russia phenakite is known only in the Urals”. 170 years have passed and still Malyshevskoye deposit remains to be the largest supplier of the best and unique samples of this rare mineral.
Quartz is one of the mostly wide-spread and profoundly- studied minerals. One may associate the word “quartz” with the image of a hexahedral prism with a pointed head. However, a detailed examination allows to infer that quartz crystals have another attributes, that may be regarded as a “visiting card” of each sample exactly identifying the place of its origin.
Transparent or semitransparent, finely painted quartz crystals have their own names: rock crystal is colourless, water-transparent; smoky quartz (cairngorm) is smoke, transparent, gray to nearly deep- brown; morion is black, semitransparent or not transparent at all; citrine is golden or lemon-yellow; amethyst is violet. There are also allochromatic colours related with the inclusions of other minerals, such as prase – greenish quartz with needles of actinolitc; avanturine – yellowish-brown with mica that develops a twinkling effect; cat’s, tiger’s or falcon’s eye shot with silk due to asbestos-like fibrous minerals; red and pink quartz with thin-dispersed iron oxides; “hairy” quartz with inclusions of ru tile.
The first official evidence of quartz crystals in the Urals may be traced back to the first half of the 17 th century.
In summer 1668 P. A. Turmashev reported to the Siberian “prikaz” on “coloured stones discovered in the vicinity of the settlement of Musrzinka, these were white, cherry and green crystals”.
The first evidence of the crystal deposits discovered in the upper reaches ot the Sanarka and Belaya rivers as well as in the vicinity of the settlement of Kundrava in the Southern Urals dates from 1750.
None of the Russian regions can be compared with the Urals in abundance and diversity of quartz deposits. A special “Hall of Quartz” is devoted to this mineral in the Ural Geological Museum. The exposition starts with a giant crystal weighing 784 kg. This is the largest of all the quartz crystals kept in the country’s museums.
Its length along the basic axle reaches 170 cm. It was found on May 26, 1966 in Tercnsaisky deposit in the Southern Urals when an excavation exposed to light a crystal-bearing cavity of about 70 cubic m. Hundreds of crystals were extracted from there, 11 of them weighed more than 500 kg each.
A sparkling collection of close relatives of the giant is displayed in the showcases of the Museum’s central hall. These are colourless and slightly smoky samples of rock crystal, morion and citrine, a particular attention should be focused on a marvelous collection of amethyst containing unique lumps and facctcd gems. One of the best collections of “hairy” quartz is also demonstrated here. It was started by Professor К. K. Matveyev. The best samples were extracted from gold- bearing fields of Neviansk region. Beautiful samples of quartz crystals with rutile needles originate from the Polar Urals.
Large number of excellent pieces and druses of rock crystal originate from the famous, world – known Polar Ural deposits “Puiva”, “Doda”, “Pyramida” and others. These deposits belong to a group of genetic type deposits of alpine veins, and supply the largest museums and private collections with gorgeous samples. Rock crystal from these deposits usually are found together with aksinitc, brukite, anatase, calcite, rutile, etc.