MAY BIRTHSTONE-EMERAID

 
Emerald is known as the king of emeralds, as rare as the bright red Ulan, and one of the four precious stones (red, blue, emerald and diamond) recognized by the international jewellery industry. Because of its unique green and unique charm, as well as magical legends, it is favored by Westerners.

Emerald symbolizes kindness, faith, kindness, eternity, luck, and happiness. Wearing it will bring peace to life. It is also a memorial stone for the 55th anniversary of marriage.

Emerald is a very old gem that has been used as jewelry in ancient Egypt.

Introduction

Emerald English is emerala, derived from Persian zumurud (Emerald), later evolved into Latin smaragdus, and rumored as esmeraude, emeraude, and then became English spelling, Chinese is transliteration. Tao Zongyi transliterated in his"helping wood thorn". The old fashions in our country are called “Mother Green” and “Help Water Green”. Hong Kong is also known as "Luzon Green". The emerald is a family of beryl, which is a hexagonal system. Crystals are often hexagonal, with few vertebrae. There are pits on the cylinder and bottom surface.

Emerald is one of the most ancient gemstone varieties, and the highest quality emerald is more valuable than diamonds. It has been used as jewelry in ancient Egypt. The famous mine at the time, Cleopatra (the name of Cleopatra), has now been exhausted by extensive mining.

Emerald is hard to find innocent gems. In fact, it can be said that there are some cracks and inclusions in the emerald gemstone, and the variety of crack inclusions is so complicated that even the researchers call it “garden”.

Emerald has been one of the precious stones since ancient times. According to legend, 6,000 years ago, there were people in Babylon who presented it to the statue of the goddess. In the ancient Chaldean countries of the Persian Gulf, women especially love emerald jewelry.

Ancient Egypt and the ancient Greeks thousands of years ago also liked to use emeralds for jewelry. Chinese people are also very fond of emeralds. The emperors of the Ming and Qing dynasties were especially emeralds. The Emperor of the Ming Dynasty regarded it as as precious as the golden-green cat's eye, and said that "the crown requires cat eyes and emeralds." Ming Wanli Emperor's jade belt is set with a large emerald, which is now in the Ming Tombs of the Ming Tombs Museum. The golden silk quilt covered by the Empress Dowager Cixi was covered with a large number of pearls and other gemstones. There are also two emeralds weighing about 5 yuan each.
Too much inclusions naturally affect the value of the gemstone, but for gemologists, the emerald's inclusions are rare samples, and by observing the different inclusions, the difference in gemstone origin can be distinguished. And its growing environment. Although the emerald's inclusions greatly affect the beauty of the gemstone, its beautiful green color is still no match for other gemstones.

The green color of the emerald comes from the chromium ions inside it, which can be observed by Charles filter. Under the Charles filter, most of the emeralds appear dark red due to the presence of chromium ions, while other green substitutes are mostly dark green. This rule can only be used as a reference for identification. It cannot be used to determine the authenticity, because some African-made emeralds are not red under the color filter. On the contrary, some artificial emeralds have a strong red color.

Due to the formation of the rock that is often subjected to stress extrusion, the appearance of the emerald crystal is almost broken, and there are many inclusions. The crystal integrity is extremely rare. The green color of emeralds is not the same as the color of other natural emeralds, and its large inclusions can be distinguished by more experienced people.

Mineral deposit cause

Since Cr and V atoms are important coloring ions of emeralds, the formation of emerald deposits requires the presence of silicon-rich aluminum bismuth and geologically relevant conditions for the supply of magnesia, chromium and vanadium, which in turn is related to ore-bearing parent rocks and surrounding rocks. The conditions for the construction of the deposit are inextricably linked. According to the above three types, the emerald deposits can be divided into three types: hydrothermal type, gas-forming hydrothermal type and pegmatite type.

Low temperature and low pressure brine hydrothermal type

Colombia produces many high-quality emeralds, and its emeralds account for more than half of the market share, and the genesis of its deposits is unique.

This type of deposit is usually formed under low temperature and low pressure conditions compared to the other two deposits. This type of deposit is formed by the infiltration of calcite into limestone or shale. This calcite is usually grayish white, and its symbiotic minerals are pyrite, quartz, albite, emerald and so on. Therefore, emeralds are mainly found in carbonated shale, limestone and various veins of carbonated and sodium-long petrochemicals. They are often formed together with minerals such as quartz, dolomite and calcite in the gaps of calcite veins.

The concentration of stress in the rock mass is concentrated, especially in the inclined end of the anticline.

The tectonic activity of deep acidic magma is the main reason for this type of deposit. The low temperature hydrothermal fluid formed by magma differentiation invades into the sedimentary rock gap of the surface, and the hydrothermal fluid rich in ore-forming elements erodes the coloration in the surrounding rock. Ions, which become emeralds. Because the emplacement is shallow, its ore-forming temperature is generally not too high, around 180°C.

The characteristic mineral combination in this type of deposit is mainly calcite-dolomite-beryl, crystals often form clusters, and the output form is mainly veins. In this type of deposit, the feldspar and carbonate minerals can be used as a prospecting mark.
Gas-forming hydrothermal type

Most emerald deposits are caused by aerothermal fluids, and the resulting emerald deposits are widely distributed in most emerald-producing countries, such as India, Zimbabwe, Australia, Pakistan, and Tanzania. Despite this, the quality of the emerald produced by the deposit is small, although Sindawana and Tanzania produce some high-quality emeralds, but still far less than Colombia.

Among the gas-forming hydrothermal emerald deposits, emeralds are mainly distributed in schist crystals such as mica, talc, and chlorite. Acidic magma invades into the rock mass (the surrounding rock is mainly superbasic), and the existing minerals metamorphose due to the heat and pressure on the contact zone. In this process, the original beryl is decomposed and metamorphosed. The lower component is gradually transferred to the mica schist and recrystallized therein. If the surrounding rock contains exactly a trace amount of Cr or V, it can form an emerald. The main ore-bearing rock mass usually has a vein-like output, which is often present near the contact zone between the intrusion and the surrounding rock, and the ore-forming temperature is around 400 °C.

Because the specific metallogenic environment will not be exactly the same, the emeralds formed a variety of mineral inclusions, but according to the formation reasons, they all contain certain mica inclusions.

Pegmatite

The pegmatite deposit is not only the main source of rare rare earth elements, but it is also associated with a genetic origin of the emerald deposit.

The emerald-producing pegmatite is divided into magma and metamorphic pegmatite. Magma pegmatites also include feldspar pegmatites containing rare or chrome-magnesium elements. They are generally in the apex, edge or fissure of the invader.

In the late stage of magmatic intrusion and segregation, due to changes in external conditions, the magma first undergoes crystallization, and then the content of the components in the acidic magma and the ultrabasic rock mass is different, and the magma is used to interpret the surrounding rock. The structural fractures undergo osmosis to form pegmatite veins. Because the pegmatite bed is mainly produced in the strong fold zone and the granite intrusion development zone, under the strong tectonic action, the surrounding rock metamorphism forms metamorphic rocks and affects the formation of minerals in the magmatic rock, eventually forming emerald. This type of deposit formation temperature is mainly between 200 ° C and 600 ° C.

This type of emerald deposit is distributed in the United States, Brazil, Australia, China, etc.

Cause of color formation

The color of emerald is very attractive. Some people describe it with spinach green, green onion and green bud green, but they can't accurately express its color. It has a yellowish green color, and it seems to have a little blue.

Even the spectrum seems to be missing the dot wavelength. It is one of the gemstones that can never be seen. Whether it is cloudy or sunny, whether it is artificial light or natural light, it always emits soft and rich light. This is the king of green gems - the charm of emeralds.
Emerald is a gem-quality green beryl. The green color should reach medium to reach a rich green tone, that is, the concentration of the color should be relatively saturated. Light green is often referred to as green beryl.

The beryl forms an emerald because it contains an appropriate amount of Cr2O3 (0.15~0.6%). It is the best member of the beryl family. The material is a high-grade gem. The source of color is: traces of chromium oxide give it a brilliant green color.

Physical and chemical ingredients

Emerald is a bismuth-containing silicate with a molecular formula of Be3Al2(SiO3)6, which is one of the most "noble" members of the beryl family. It belongs to the hexagonal system. The crystal form is a hexagonal column, a hexagonal double cone, and most of them are rectangular columns. The aggregate is granular, massive, and the like.

Emerald green, glass luster, transparent to translucent. The refractive index is 1.564-1.602, the birefringence is 0.005-0.009, the chromaticity is medium to strong (blue-green, yellow-green), and the heterogeneous body. Hardness 7.5, density 2.63-2.90 g / cm3. The cleavage is incomplete, and the shell-like fracture. Brittle. Under X-rays, the emerald emits a weak, pure red fluorescence. [3] Absorption spectra: strong absorption lines of 683 nm and 680 nm, weak absorption lines of 662 nm and 646 nm, partial absorption bands of 630 nm to 580 nm, and full absorption of the purple region. Special optical effects: cat eye effect, star effect (rare).

Optimization processing

Due to the excessive number of cracks, the optimization of emerald treatment is mainly in dealing with cracks.

The most famous optimization treatment of emerald is immersion oil treatment. If the crack of emerald extends to its surface, it will be soaked with a special kind of grease, so that the crack is less obvious due to oil immersion. On many poor quality emeralds. Sometimes the crack inlet is covered with special materials after the oil immersion treatment to avoid oil leakage.

The crack identification method is as follows:

Dip colorless oil: the surface crack is colorless or light yellow; it can be yellow-green or green-yellow fluorescence under long-wave ultraviolet light; the hot needle can be separated by oil, and the organic matter can be determined by infrared spectroscopy.

Immersed in color oil: the surface crack is green; the long-wave ultraviolet light is yellow-green or green-yellow; the acetone cotton swab is lightly green, and the organic matter is determined by infrared spectroscopy.

Filling treatment: There is a “flash effect” at the surface crack; the acetone swab can be dissolved under the microscope to dissolve the filling; the hot needle can be melted and filled.

Special effect

Since being discovered by humans, emeralds have been regarded as a magical force to exorcise evil spirits. People use emeralds as amulets, shuns or religious ornaments, and believe that wearing them can resist the invasion of viper and beasts.

Cut

Many people who know the knowledge of emerald cut work think that it is synonymous with color. In fact, emerald also represents a kind of cut. It is a kind of exquisite cut of zircon rectangular, with good gloss and level. Feeling, it is used by more people as a method of gem cutting.

Variety classification

Classified by special optical effects

Emeralds can be divided into four varieties according to the presence or absence of special optical effects and special phenomena: emeralds, emerald cat eyes, starlight emeralds and Dabiz emeralds.

(1) Emerald. It is a green grandmother without any special optical effects.

(2) Emerald cat eyes. It is an emerald with a cat's eye effect. Emeralds in nature are very rare, and emeralds with cat-eye effects are rare and rare. Therefore, emerald cat eyes are very expensive.

(3) Starlight emerald. It is an emerald with a star effect. Emeralds with a star effect are less expensive than emerald cat eyes, so they are more expensive.

(4) Dabiz Emerald
The Tractiche Emerald is characterized by a hexagonal black stripe radiating from the center and a hexagonal transparent or black core in the middle. Because of its shape resembling the grinding wheel used by the Spanish to squeeze sugar cane (Spanish: tra·pi·che (de azúcar)), it is named after this. The cause is that during crystal growth, the emerald crystal compresses the impurities between the hexagonal growth faces.

In the middle of the green emerald, there are black (dark) nucleus and radial arms, which are composed of carbonaceous inclusions and albite, and rare calcite and pyrite.

Dapex Trapiche is not a gem, but a special growth phenomenon of gemstones. It is not only found in emeralds. It should be said that all the trigonal or hexagonal gemstones may have Dabiz. The Dabize structure consists of a unique hexagonal and radial spiral arm ribbon, as well as tiny cloud-like inclusions.

The most famous Dabbie structure appears in emeralds, in which aquamarine, ruby, sapphire, tourmaline, crystal, andalusite, cordierite, etc. all have Dabiz structure phenomenon.

Most of the quality emeralds are produced in Colombia, and the Dabbies emerald must be produced in Colombia?
In fact, not necessarily, Brazil also found the Dabies emerald.

Main producing area

The main producing areas of emerald are Colombia, Russia, Brazil, India, South Africa, Zimbabwe, China, etc. The most common emeralds on the international market come from three origins: Colombia, Brazil and Zambia.

Colombia

The emerald produced in Colombia is famous for its good color, good texture and high yield. It is the world's largest high quality emerald producing area. The two most important emerald deposits in Colombia are Muzo and Chivor, which are located about 100 km northeast of Bogotá, in the Cordillera Mountains. Colombian emeralds began production in the mid-16th century, when the emerald mine was owned by the occupiers of the Spanish, and it was not state-owned until 1886. For centuries, the Muzuo and Cheval mines have been the world's largest supply of quality emeralds, monopolizing the international market, accounting for about 80% of the world's total quality emerald production.

Colombian emeralds are mainly produced in the calcite and feldspar veins of the sedimentary rock series.

The surrounding rocks are carbonaceous shale and limestone. The calcite veins containing emeralds, the dolomite veins of dolomite, and the pyrite veins of pyrite are generally 60 meters long. It is 0.1 to 20 cm wide and has a vein and a vein. Emerald is plaque-like in the veins. The emerald is a columnar crystal with an average length of 2 - 3 cm and a light green to dark green color. Slightly blue, good texture and transparency.

Carbon monoxide bubbles, liquid-liquid three-phase inclusions such as liquid sodium chloride and cubic salt are found in emerald crystals, which is very rare in emeralds in other regions, only Colombian emeralds.

In addition, there are often inclusions such as pyrite, black carbonaceous materials, crystals, and chromite. It is generally believed that the slightly blue emerald green emerald in the Chival mining area is the best in quality and is considered to be the most beautiful emerald in the world. In 1969, a huge emerald weighing 7025 carats was found in Colombia. The emeralds produced in Colombia have long been known around the world, and one of the lesser-known Dabiz grainy emeralds is unique in the world.

In 1946, this rare emerald gemstone, Dabiz, was first discovered in the famous mining area of ​​Muzo, Peru.

The original meaning of Spanish was: grinding sucrose. Because the center of the gem has a hexagonal core, which radiates a six-line line like the sun, forming a star-shaped pattern, hence the name.

The locals are convinced that this is a special gift from God. Every line represents blessings: health, wealth, love, luck, wisdom, happiness. Because of the special nature of the gemstones, they are polished to a curved surface without planar cutting. With the closure of the Biblanka mine, the existing Dalbez is more and more precious. The Star of Andes, now in the British Empire, London Victoria and Abbott Museum: weighs 80.61 carats.

Colombian emerald is recognized as the best in the world, its color is pure green, a few are yellow-green or blue-green; cracks are more, carbon monoxide bubbles, liquid sodium chloride and cubic salt are visible in the crystal, liquid, solid Three-phase inclusions - this feature is unique to Colombian emeralds, as well as fibrous inclusions, pyrite inclusions, yellow-brown granular fluorocarbon calcium strontium inclusions, quartz inclusions, pyrrhotite inclusions And molybdenum ore inclusions.

Russia

The Russian Ural emerald was discovered by a farmer in 1831 and the mining area is located near Sverdlovsk.

Thousands of carats of high-quality emeralds have been produced for over a century. The deposit is produced in the phlogopite quartzite of the ultrabasic rock, which is a metamorphic ultrabasic rock in which many granitic pegmatites and fine-grained rocks invade. Emeralds are uneven plaques in mica rock.

The emerald is light green and dark green with a slight yellow hue. Most of them are columnar crystals, sometimes flat plate crystals, with an average length of 3 to 5 cm. Emerald crystals often contain amphoteric inclusions, irregularly arranged, and biotite inclusions, which are leaf-like and scaly. The minerals of emeralds are apatite, phlogopite and the like.

South Africa

The South African (Azania) emerald deposit was discovered in 1927. The deposit is located in the biotite schist and biotite-chlorite schist near the pegmatite contact zone. The formation of emeralds is the same as the volatile-rich high-temperature gas. The formation of hydrothermal fluids is closely related to the interaction of ultrabasic rocks.

The emerald crystal is a flattened plate containing biotite and sulfide inclusions. The emerald color has a banding phenomenon, from light green to dark green, and the crystal is generally 3-5 cm long.

The emeralds located in the northeastern deposit of Transvaal in South Africa are of very high quality, but the crystals are small, and the associated minerals are tourmaline, gold emerald, topaz and so on. South Africa is still one of the world's leading producers of emeralds. In 1956, it discovered a 24,000-carat high-quality emerald crystal, the world's largest emerald crystal.
Zimbabwe

The Zimbabwe Emerald Deposit was discovered in 1957. The output is very large and has become a major exporter of emerging emeralds in the world. The deposit is produced in Archean crystalline rock, and the surrounding rocks are diaphonic schist and chlorite schist. Emeralds are unevenly distributed phenocrytic output.

The ore body is 300-500 meters long, 0.2--10 meters thick and 100-200 meters deep. Emeralds are less than 10% in the ore belt. The high-quality emerald accounts for 5% of the total newly produced emeralds.

The emerald is a hexagonal columnar body with an average crystal grain size of 1-3 mm and a large crystal size of 3 cm. The emerald has a small particle size but high quality and high quality. Green, very beautiful, associated minerals such as gold emeralds.

Brazil

There are many Brazilian emeralds, but the emerald crystals are small and sturdy. In 1962, high-quality emeralds were discovered in Bahia. Brazil's emerald minerals are mostly located in the northeast, especially in Bahia. Most of the modern high-quality emeralds are still produced in South America.

The crystals are almost completely transparent and brightly colored, which is comparable to Colombian emeralds.

Zambia

Zambia's emerald quality is a surprise: the emeralds produced in the area have good transparency and rich emerald green, often with a slight blue tint, which is very beautiful. The quality of quality people can be comparable to that of Colombia.

Tanzania

In 1970, a high quality emerald deposit was discovered in the National Park on the west bank of Lake Manyara, Tanzania. Emerald is produced in the veins of massive pegmatite and biotite schist.

The formation of emeralds is related to the interaction of granitic pegmatites into metamorphic ultrabasic rocks. The emerald-containing mica rocks are often associated with pegmatite veins, and the minerals associated with emeralds are gold emeralds, garnets, reds, sapphires, apatites, and the like.

The emerald color is pale yellowish green, light green and light green, and the crystal is small, generally 0.1 to 5 cm, and the largest is 4 cm.

Pakistan

The Pakshawa emerald deposit in Pakistan was discovered in 1958, and the deposit extends northeastward with an area of ​​180 mu. The surrounding rock is a talc schist with snake veins invading, and a large number of reticulated hydrothermal quartz veins are mineralized. The emerald enrichment in the lower talc schist is cystic.

Emerald formation is related to the contact metamorphism between the granitic pegmatite and the chromium-bearing metamorphic rocks. The emerald crystals in the quartz vein are broken, and the emerald crystals in the talc schist are intact, dark green, transparent, and most crystals are larger than 1 carat, but most contain inclusions. Premium emeralds can be compared to Colombian emeralds.

India

The emerald deposit in Rajasthan, India, was discovered in 1943. The emerald-bearing ore belt is large in size, 200 kilometers long from north to south and 30 kilometers wide.

The emerald formation is related to the intrusion of the granitic pegmatite into the metamorphic ultrabasic rocks. The emerald is unevenly distributed with porphyry, and the surrounding rock is strongly mixed lithified biotite schist and gneiss.

The emerald crystal is small, has many cracks, and the quality is poor. The crystal is columnar and flat, with an average length of 3-5 cm. The color is light green to dark green, transparent and translucent.

Australia

The Australian Perth Emerald Deposit began mining in 1909 and is the only emerald mine in Australia. The deposit is produced in the mica schist of metamorphic ultrabasic rock invaded by granitic pegmatite, which is a volatile high temperature gasification heat.

An emerald deposit formed by the action of liquid and ultrabasic rocks. The emerald crystal is hexagonal, 2 cm long, light green or yellowish green. Emerald crystals contain less inclusions of impurities and a higher overall quality. Gem-quality emeralds account for 11% of the total emeralds mined.

Afghanistan

There is also Afghanistan in the emerald-producing area. The emerald grows in the hydrothermally altered marble and mica schist, and the Huichang-long diorite rock wall. It is produced in a 2.3-meter-thick, 10-meter-long quartz-micro plagioclase Carbonate veins.

The emerald is dark green, less transparent, and generally 1-1.5 cm long. In 1973, the largest crystal was 2.8 cm.

Austria

Salzburg, Austria is the only emerald producing area in Europe, and some emeralds have been produced in the Middle Ages. The emeralds here are small in size and rarely exceed 1-2 carats.

Moreover, it is a low-quality emerald.

Emerald origins are also in North Carolina, Norway, etc. in the United States. Some emerald-like crystals have also been found in Yunnan, China, and they can be considered emeralds regardless of their color, composition and chromium oxide content. The crystal length is 5-8cm, it is light green, multi-envelope, a lot of transverse cracks, more opaque or translucent, is a low-grade emerald, can only honed plain gemstones.

Emerald is produced in the old metamorphic schist, which is said to be large in scale and extremely distant. Emeralds are distributed in many countries.

China

Mainly produced in Xinjiang Hetian, Xinjiang emerald is blue-green, and medium yellow-green, blue-green pleochroism. There are very few gem grades.

Quality identification

1. Color: The color with green and blue is better, and the quality with green and gray is worse.

2. Transparency: It is a clear and bright, crystal clear and transparent, and translucent is an ordinary product.

3. Purity: The interior of emeralds often has some inclusions, such as pure ones, which are rare top grades.

4. Cut: The standard cut is called emerald type, which can completely reflect the luster of the gem.

5. Weight: The crystals of ordinary emeralds are not large. After cutting, the quality is excellent, and the weight is more than 2 carats. It is rare. If the weight is above 5 carats, it is a rare treasure.

synthetic

Emerald green is not the same color as other natural emeralds, and its large inclusive features can be distinguished by more experienced people. As for synthetic gems, the effort to synthesize emeralds can be said to be a successor. Basically, synthetic emeralds are made by hydrothermal methods rather than Vilnius.

There is a limitation in the manufacture of synthetic gemstones by the Vilnius method, which is only suitable for the synthesis of oxide-based gemstones such as corundum and spinel, which are crystallized into droplets by the Viennese method. During the process, only oxides can crystallize quickly.

Emerald is a silicate and therefore does not apply to the Vilnius method. The synthetic emerald of Princess Cut should actually be a spinel-type synthetic product because almost no dichroism is observed and no inclusions from the flux are visible.

The emerald hydrothermal process content is mainly to put the seed crystal into the solution containing the emerald component, so that it slowly crystallizes, the gems after crystallization are pure and flawless, and the contents of many emeralds with natural emeralds Not quite.

Therefore, the imitation will add some flux in the process, so that the artificial emerald can produce natural cloud-like inclusions after crystallization, and the shape of the inclusions varies depending on the type of flux. It often forms a very interesting pattern.

Distinguishing discrimination

The difference between emerald and similar natural green gemstones, synthetic emeralds, and fakes. Similar natural green gemstones are fluorite, green tourmaline, apatite, jade, green sapphire, chrome vanadium calcium aluminum garnet; artificial emeralds and imitations with synthetic emerald, beryl three-layer stone, foil-lined grandmother Green, oiled emeralds, etc. The difference is as follows: fluorite, microstrip blue green, homogeneous body, hardness, 4, density 3.18 g / cm3, larger than emerald, fluorescent light blue.

Green tourmaline, dark blue green tourmaline changed to pure green, with obvious dichroism, high birefringence, 0.18, high density. Apatite, light blue apatite with a blue color, has a blue hue, a hardness of 5, a large refractive index of 1.632-1.667, and phosphorescence under ultraviolet light.

Emerald, high-quality translucent emerald green jade is more like emerald, but jade has a fiber interweaving structure, with finer fibers, emerald does not have this structure. In addition, it contains chrome vanadium calcium aluminum garnet, emerald green, homogeneous body, strong argon diamond.

Synthetic emerald, flux growth method and hydrothermal synthesis, the color is rich, there is strong red fluorescence under ultraviolet light, and the color is bright red under the color filter. There are also beryl three-layer stone, foil-lined emerald, oil-filled emerald, etc., which can be distinguished from emeralds by careful observation and identification.

Synthetic gemstones similar to emeralds include synthetic emeralds, YAG (yttrium aluminum garnet), and green glass. Among them, the distinction between natural emerald and YGA and glass can be carried out according to the following two points:

1. Natural emeralds are mostly flawed and cracked. This is similar to ruby. Most of them are "cotton", sometimes with some black mineral inclusions and other impurities. The synthetics are mostly clean or have a small amount. bubble.

2. Emerald is visible in dichroism. Viewed from different directions, the gemstone is emerald-blue-green or yellow-green, while both glass and YAG have only one color.

The difference between natural emeralds and synthetic emeralds is mostly done in the laboratory.

The main differences are:

(1) The natural emerald has a refractive index generally between 1.57-1.59, while synthetic emeralds tend to have a low refractive index, generally less than 1.57, with exceptions.

(2) The proportion of natural emeralds is relatively large, generally greater than 2.7, while the emeralds synthesized by fusion method have a specific gravity of only 2.65-2.66. However, it should be noted that the hydrothermally synthesized emerald also has a higher proportion.

(3) Most of the natural emeralds will have enamel and three-phase inclusions.
The synthetic emeralds such as needle-like, columnar, and granular crystalline mineral inclusions tend to be relatively clean.

The hydrothermally synthesized emerald inclusions are “window screens”. The emerald inclusions synthesized by fusion method are in the form of bread crumbs.

Natural and synthetic emeralds have different inclusion characteristics.

(4) Natural emeralds are relatively slow to react under ultraviolet light, or dark red, while synthetic emeralds tend to produce strong red fluorescence. This test should generally be compared to the standard.

Maintenance common sense

(1) Do not touch the acid or alkali, and do not rub against other stones or metals to avoid scratches on the surface of the stone.

(2) Clean water. Emeralds are often oiled to mask cracks and increase transparency.

Therefore, when cleaning emerald jewelry, if you use acid, alkali, alcohol, ether, etc., it will destroy the filling material in the crack and reduce its transparency.

Therefore, it is best to wash the emerald jewelry with water. Emerald jewelry cannot be cleaned with ultrasound, as it may cause irreparable damage to the stone.

Gem culture

The name of the emerald comes from the Greek word “Smaragdos”, which is derived from the old French “Esmeralde”, meaning green gems. Numerous wonderful stories have been around this magnificent emerald since ancient times.

Today's finest emeralds are still produced in South America, while the Incas of South America regard emeralds as sacred gems.

However, it is only said that the oldest emerald was once found near the Red Sea in Egypt. Having said that, the mines in this place were already mined in ancient Egypt between 3000 and 1500 BC, and later called (Cleopatra's Mines) - Cleopatra (the name of Cleopatra), which was in the early 19th century.

When it was discovered again, it was exhausted due to mass mining.

One of the world's largest emeralds, "Mogul Emerald", was discovered in 1695 and weighed 217.80 carats, about 10 centimeters high.

On one side is engraved with prayers and on the other side is engraved with magnificent floral ornaments.

The legendary emerald was bought by an anonymous buyer for $220 million at the Christie's auction in London on September 28, 2001.

Emerald has been respected since ancient times.

For this reason, the most famous emeralds are often kept in museums. Take the New York Museum of Natural History as an example. A pure emerald cup belonging to the Emperor Jehangir was exhibited.

On the side of the show is "Patricia", one of the world's largest Colombian emerald rough stones, which weighs 632 carats. Bogotá Bank also collects five precious emerald roughs weighing between 220 and 1796 carats, and these brilliant emeralds are part of the Iranian national treasury, which is used to decorate the crown of former Queen Warach. The Sultan of Turkey also loves emeralds.

Every piece of jewellery, writing tools and daggers displayed at the Topkapi Palace in Istanbul is reluctant to decorate with emeralds and other precious stones.

It is known that the earliest emeralds were produced from schist deposits in southeastern Cairo, Egypt.

Excavated by slave labor in 1500 BC or earlier, from ancient times to the 18th century, it was in turn owned by Egyptians, Greeks, Romans and Turks. It was abandoned in 1740 due to the depletion of resources, and all the information was lost, so that some people thought that there had never been emeralds, but all imported goods.

Egyptian emeralds have actually been difficult to identify, and no samples have been preserved to be known.

Central and South America are the main producers of emeralds in the world. As early as 1521 when Spain invaded Mexico, there was a record of looting emeralds. In 1532, when Spain invaded Peru, the aggressors offered the plundered emerald as a gift to the king in order to please the king.

The green of emerald is the color of life and spring, starting every year. Moreover, centuries has been the color that represents the beauty and eternal love. In ancient Rome, green is the color of Venus - the goddess of love and beauty. Today, many cultures and religions still have a special status.

For example, Islam sees green as a sacred color. The flags of many Arab League countries use green as a symbol of unity and unity. Not only that, the Catholic Church also believes that green is the most natural and the most basic color in etiquette.

The beautiful green of emerald conveys harmony, natural love, and a happy life.

The unique color of emerald is always awesome. Historian Pliny once said that green delights our eyes.

The fresh, vivid image of green is never monotonous.

Even if the emerald green color changes due to the sunny or cloudy day, the natural light source is different from the artificial light source, it always vividly emits different soft and rich light.