Emerald mining

Je ryl was probably not used in Egypt before Ptolemaic times (87). A. Lucas stated that the mines in the Red Sea hills, which were mentioned by Strabo and Pliny the Elder, were probably the only source of beryl in ancient times (87). In 1817 F. Cailliaud discovered the emerald mines near Mt. Zabara nearly in the same state in which they had been left by the engineers of the Ptolemies. He penetrated into a vast number of excavations and subterraneous canals, some of which are so deep that four hundred men may work in them at once.. .. M. C. himself set about working the mines, and he has presented six pounds of emeralds to Mahommed Ali Pashaw (88). 

Emerald is a variety of beryl, a beryllium silicate, with a hardness of 7.5 to 8. It has a beautiful deep green color, and it is one of the most expensive gems, sometimes outranking diamond in value. The green color results from small amounts of chromic oxide (Cr203). The oldest emerald mines were in Egypt near the Red Sea, but the best emerald mines today are in Colombia. There are others in Brazil, Pakistan, and Africa synthetic emeralds of excellent quality have also been manufactured. 

The emerald has been prized from very early times and Cleopatra s Emerald Mines in Upper Egypt were worked in 1650 B.c.— many1 centuries before that famous queen saw the light. Stones with a bluish-green cast are known as aquamarines and H.M. Queen Elizabeth is said to have a collection of these, her favourite stones. The aquamarine is regarded as a lucky stone. 

AF Laskovenko, VI Zhemakov. An update on the Ural emerald mines. Gems Gemol 31 106-113, 1995. 

In 1799 Citizen Tassaert, a Prussian chemist who had been working for several years at the School of Mines of Paris, discovered chromium in an iron mineral found at the Carrade Villa near Gassin in the department of du Var. He too regarded the mineral as a chromate of iron (89). Since chromium had previously been detected in the red lead of Siberia (crocoite), in the emerald, and in the ruby, the chrome-iron mineral... 

In the Muzo and Chivor mines, in Colombia, calcite veins, in which emerald crystals occur, develop, and they fill the cracks of sedimentary slate rock. Compared with emeralds occurring in basic metamorphic rocks, like those in the Urals, South Africa, or India, Colombian emerald crystals have a higher perfection, fewer inclusions, and attract higher evaluations as gemstones, since crystals grew freely in a hydrothermal solution. 

In the Muzo and Chivor mines, emerald single crystals with a particular texture... 

The Emerald and Topaz are stones of the same class, dry and cold. They are found in gold mines. The best are the clearest, greenest and most transparent. By long gazing upon the emerald, weakness of the eyes is cured. 

EMERALD. This beautiful green variety of the mineral beryl has been known since ancient times and always prized as a gem. both because of its color ami relative rarity. It is frequently cloudy or flawed, hence the expression rare as an emerald without a flaw." The original source of emeralds seems to be the so-called Cleopatra s mines in Egypt, where in a range of low mountains about 15 miles (24 kilometers) from the Red Sea. they arc found in schists. The quality uf these emeralds is not high, but there is much evidence of considerable workings in a former period. See also Beryl. 

Jasper, on the one hand, similar to emerald, on the other, cerulean, obtained by mining. 

In 1797, chromium received its name from a professor of chemistry and assaying at the School of Mines in Paris, Nicolas-Louis Vauquelin. He received some samples of crocoite ore and his subsequent analysis revealed a new metallic element, which he called chromium after the Greek word khroma, meaning color. After further research he detected trace elements of chromium in precious gems - giving the characteristic red color of rubies and the distinctive green of emeralds, serpentine, and chrome mica. 

A gem closely related to ruby and emerald is alexandrite, named after Alexander II of Russia. This gem is based on the mineral chrysoberyl, a beryllium aluminate with the empirical formula BeO AI2O3 in which approximately 1 % of the Al + ions are replaced by Cr ions. In the chrysoberyl environment Cr + absorbs strongly in the yellow region of the spectrum. Alexandrite has the interesting property of changing colors depending on the light source. When the first alexandrite stone was discovered deep in a mine in the... 

The finest specimens occur in the Muzo mines, Colombia. Other occurrences include the Ural Mountains, the Transvaal in South Africa, and Kaligunan in India. Emeralds can also be successfiiUy synthesized. 

In Columbia the Muzo mine, 100 km north-west of the capital Bogota was mined by the Incas, was forgotten, but was rediscovered in the 17 century, and mining is still going on. In Colombia there is also an eastern emerald belt Colombian emeralds... 

Lehmann was not the first to observe the green color of chromium. As early as 2000 Bc, emeralds were extracted from mines by the Red Sea, later called Cleopatra s mines. Emerald is an aluminum beryUium sihcate, a beryl. It has its beautiful green color just from chromium. Emerald is the noblest gem in the beryl group, nobler than the yeUow precious beryl and the blue aquamarine. There are many large emeralds that compete with diamonds and rubies in value and celebrity. Today the biggest and most beautiful emeralds are found in Columbia. 

A gemstone is a mineral that can be cut and polished to make gems for an ornament or piece of jewelry. At one time, all gemstones were naturally occurring minerals mined from Earth s crust. Today, however, chemists can duplicate natural processes to produce artificial gemstones. Amethyst, emerald, jade, opal, ruby, sapphire, and topaz occur naturally and can also be produced synthetically. 

Strabo (63 B.C. - 24 A.D.) writes about mines within the Roman world in his Geography. Among the specific t5 es of mines mentioned were iron, copper, arsenic, gold, silver, lead, tin and emerald, but not a word about sulfur mines. He goes on to report that all sorts of mines existed in Italy (6.4.1), and of ancient copper mines at Temesa, in south-western Italy, near Sicily (6.1.5 12.3.23). No mining in Sicily itself was reported. 

Kenora, Ontario, and Emerald Field Resources Big Mack petalite deposit near Kenora, Canada and the now-closed Tin-Spodumene Belt of Foote and FMC in North Carolina, USA. There are large commercial deposits in China, Russia and Zaire (the latter with limited lithium production), and medium-sized ones in Brazil, Namibia, Portugal, Finland and Afghanistan (the latter two not yet mined in 2002 Sailer and O Driscoll, 2000). In the past, and a few at present, of the smaller deposits throughout the world have had limited mining, such as in Rwanda, South Africa and Europe. The major commercial lithium minerals in these deposits are described in the following section. 

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