Jewelry

Monday, January 21, 2013

Opal:

Opal is an amorphous form of silica , a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl and basalt. Opal is the national gemstone of Australia, which produces 97% of the world's supply.[4] This includes the production of the state of South Australia, which amounts to around 80% of the world's supply.

Opal's internal structure makes it diffract light; depending on the conditions in which it formed it can take on many colors. Opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare, whereas white and greens are the most common. It varies in optical density from opaque to semi-transparent. For gemstone use, its natural color is often enhanced by placing thin layers of opal on a darker underlying stone, like basalt.

Precious opal shows a variable interplay of internal colors and even though it is a mineraloid, it has an internal structure. At micro scales precious opal is composed of silica spheres some 150 to 300 nm in diameter in a hexagonal or cubic close-packed lattice. These ordered silica spheres produce the internal colors by causing the interference and diffraction of light passing through the microstructure of the opal.[6] It is the regularity of the sizes and the packing of these spheres that determines the quality of precious opal. Where the distance between the regularly packed planes of spheres is approximately half the wavelength of a component of visible light, the light of that wavelength may be subject to diffraction from the grating created by the stacked planes. The spacing between the planes and the orientation of planes with respect to the incident light determines the colors observed. The process can be described by Bragg's Law of diffraction.

Visible light of diffracted wavelengths cannot pass through large thicknesses of the opal. This is the basis of the optical band gap in a photonic crystal, of which opal is the best known natural example. In addition, microfractures may be filled with secondary silica and form thin lamellae inside the opal during solidification. The term opalescence is commonly and erroneously used to describe this unique and beautiful phenomenon, which is correctly termed play of color. Contrarily, opalescence is correctly applied to the milky, turbid appearance of common or potch opal. Potch does not show a play of color.

The veins of opal displaying the play of color are often quite thin, and this has given rise to unusual methods of preparing the stone as a gem. An opal doublet is a thin layer of opal, backed by a swart mineral such as ironstone, basalt, or obsidian. The darker backing emphasizes the play of color, and results in a more attractive display than a lighter potch.

Combined with modern techniques of polishing, doublet opal produces similar effect of black or boulder opals at a mere fraction of the price. Doublet opal also has the added benefit of having genuine opal as the top visible and touchable layer, unlike triplet opals.

The triplet-cut opal backs the colored material with a dark backing, and then has a domed cap of clear quartz or plastic on top, which takes a high polish and acts as a protective layer for the opal. The top layer also acts as a magnifier, to emphasize the play of color of the opal beneath, which is often of lower quality. Triplet opals therefore have a more artificial appearance, and are not classed as precious opal.

Superstitions of Opal
In the Middle Ages, opal was considered a stone that could provide great luck because it was believed to possess all the virtues of each gemstone whose color was represented in the color spectrum of the opal.It was also said to confer the power of invisibility if wrapped in a fresh bay leaf and held in the hand.Following the publication of Sir Walter Scott's Anne of Geierstein in 1829, however, opal acquired a less auspicious reputation. In Scott's novel, the Baroness of Arnheim wears an opal talisman with supernatural powers. When a drop of holy water falls on the talisman, the opal turns into a colorless stone and the Baroness dies soon thereafter. Due to the popularity of Scott's novel, people began to associate opals with bad luck and death.] Within a year of the publishing of Scott's novel in April 1829, the sale of opals in Europe dropped by 50%, and remained low for the next twenty years or so.

Even as recently as the beginning of the 20th century, it was believed that when a Russian saw an opal among other goods offered for sale, he or she should not buy anything more since the opal was believed to embody the evil eye.
Opal is considered the birthstone for people born in October or under the sign of Scorpio and Libra.

Middle Ages
The Middle Ages is a period of European history that lasted from the 5th until the 15th centuries. It began with the collapse of the Western Roman Empire, and was followed by the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the traditional division of Western history into Classical, Medieval, and Modern periods. The period is subdivided into the Early Middle Ages, the High Middle Ages, and the Late Middle Ages.
In the Early Middle Ages, depopulation, deurbanization, and barbarian invasions, which began in Late Antiquity, continued. The barbarian invaders formed new kingdoms in the remains of the Western Roman Empire. In the 7th century North Africa and the Middle East, once part of the Eastern Roman Empire (the Byzantine Empire), became an Islamic Empire after conquest by Muhammad's successors. Although there were substantial changes in society and political structures, the break with Antiquity was not complete. The still sizeable Byzantine Empire survived and remained a major power. The empire's law code, the Code of Justinian, was widely admired. In the West, most kingdoms incorporated extant Roman institutions, while monasteries were founded as Christianity expanded in western Europe. The Franks, under the Carolingian dynasty, established an empire covering much of western Europe; the Carolingian Empire endured until the 9th century, when it succumbed to the pressures of invasion — the Vikings from the north; the Magyars from the east, and the Saracens from the south.
During the High Middle Ages, which began after AD 1000, the population of Europe increased greatly as technological and agricultural innovations allowed trade to flourish and crop yields to increase. Manorialism — the organization of peasants into villages that owed rent and labor services to the nobles; and feudalism — the political structure whereby knights and lower-status nobles owed military service to their overlords, in return for the right to rent from lands and manors - were two of the ways society was organized in the High Middle Ages. The Crusades, first preached in 1095, were military attempts, by western European Christians, to regain control of the Middle Eastern Holy Land from the Muslims. Kings became the heads of centralized nation states, reducing crime and violence but making the ideal of a unified Christendom more distant. Intellectual life was marked by scholasticism, a philosophy which emphasized joining faith to reason, and by the founding of universities. The mathematics of Fibonacci and Oresme, the philosophy of Thomas Aquinas, the paintings of Giotto, the poetry of Dante and Chaucer, the travels of Marco Polo, and the architecture of Gothic cathedrals such as Chartres are among the outstanding achievements of this period.

The Late Middle Ages were marked by difficulties and calamities, such as famine, plague, and war, which much diminished the population of western Europe; in the four years from 1347 through 1350, the Black Death killed approximately a third of the European population. Controversy, heresy, and schism within the Church paralleled the warfare between states, the civil war, and peasant revolts occurring in the kingdoms. Cultural and technological developments transformed European society, concluding the Late Middle Ages and beginning the Early Modern period.



The magic of Ruby

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. The ruby is considered one of the four precious stones, together with the sapphire, the emerald, and the diamond.

Prices of rubies are primarily determined by color. The brightest and most valuable "red" called pigeon blood-red, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Cut and carat (weight) are also an important factor in determining the price.

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissanite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissonite falling somewhere in between corundum (ruby) and diamond in hardness. Ruby is α-alumina (the most stable form of Al2O3) in which a small fraction of the aluminium3+ ions are replaced by chromium3+ ions. Each Cr3+ is surrounded octahedrally by six O2- ions. This crystallographic arrangement strongly affects each Cr3+, resulting in light absorption in the yellow-green region of the spectrum and thus in the red color of the gem. When yellow-green light is absorbed by Cr3+, it is re-emitted as red luminescence. This red emission adds to the red color perceived by the subtraction of green and violet light from white light, and adds luster to the gem's appearance. When the optical arrangement is such that the emission is stimulated by 694-nanometer photons reflecting back and forth between two mirrors, the emission grows strongly in intensity. This effect was used by Theodore Maiman in 1960 to make the first successful laser, based on ruby.

Generally, gemstone-quality corundum in all shades of red, including pink, are called rubies.[3][4] However, in the United States, a minimum color saturation must be met to be called a ruby, otherwise the stone will be called a pink sapphire.[3] This distinction between rubies and pink sapphires is relatively new, having arisen sometime in the 20th century. If a distinction is made, the line separating a ruby from a pink sapphire is not clear and highly debated. As a result of the difficulty and subjectiveness of such distinctions, trade organizations such as the International Colored Gemstone Association (ICGA) have adopted the broader definition for ruby which encompasses its lighter shades, including pink.

Diamonds are graded using criteria that have become known as the four Cs, namely color, cut, clarity and carat weight. Similarly natural rubies can be evaluated using the four Cs together with their size and geographic origin.

The Value of Ruby
Color: In the evaluation of colored gemstones, color is the single most important factor. Color divides into three components; hue, saturation and tone. Hue refers to "color" as we normally use the term. Transparent gemstones occur in the following primary hues: red, orange, yellow, green, blue, violet. These are known as pure spectral hues.[11] In nature there are rarely pure hues so when speaking of the hue of a gemstone we speak of primary and secondary and sometimes tertiary hues. In ruby the primary hue must be red. All other hues of the gem species corundum are called sapphire. Ruby may exhibit a range of secondary hues. Orange, purple, violet and pink are possible.

 The finest ruby is best described as being a vivid medium-dark toned red. Secondary hues add an additional complication. Pink, orange, and purple are the normal secondary hues in ruby. Of the three, purple is preferred because, firstly, the purple reinforces the red making it appear richer.[11] Secondly, purple occupies a position on the color wheel halfway between red and blue. In Burma where the term pigeon blood originated, rubies are set in pure gold. Pure gold is itself a highly saturated yellow. Set a purplish-red ruby in yellow and the yellow neutralizes its complement blue leaving the stone appearing to be pure red in the setting.

The Ruby zodiac, myth & legend
For a long time India was considered as the classical source of rubies. In the Sanskrit language ruby is called "ratnaraj", which translates as "King of Gemstones".

In ancient times one of the chief attractions of ruby has been its protection from misfortune and bad health.

Ruby is the birthstone for those who are born in July. On the Zodiac chart, ruby is the stone for Capricorn.
Ruby is also used to celebrate a couple's 15th and 40th anniversary.

In Antiquity, as well as in the Middle Ages people believed that the cosmos is reflected in gemstones. The ruby is assigned to the planets Mars and Pluto. The esoteric movement revived the ancient belief and the gem industry made it another marketing tool to promote certain gems.

The healing powers of gems remain a controversial issue, but are mentioned for centuries by healers, shamans and medicine men. Whether it's a fact or a placebo effect doesn't matter, if it helps. The safest approach is to wear the gemstone in skin contact to the troubled part of the body. Ruby is said to be a general health protection and a help for backache and toenail problems.





Saturday, January 19, 2013

Topaz

Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and other faces.

Topaz is commonly associated with silicic igneous rocks of the granite and rhyolite type. It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows like those at Topaz Mountain in western Utah. It can be found with fluorite and cassiterite in various areas including the Ural and Ilmen mountains of Russia, in Afghanistan, Sri Lanka, Czech Republic, Germany, Norway, Pakistan, Italy, Sweden, Japan, Brazil, Mexico; Flinders Island, Australia; Nigeria and the United States.
Some clear topaz crystals from Brazilian pegmatites can reach boulder size and weigh hundreds of pounds. Crystals of this size may be seen in museum collections. The Topaz of Aurangzeb, observed by Jean Baptiste Tavernier measured 157.75 carats. The American Golden Topaz, a more recent gem, measured a massive 22,892.5 carats. Colorless and light-blue varieties of topaz are found in Precambrian granite in Mason County, Texas within the Llano Uplift. There is no commercial mining of topaz in that area.

The name "topaz" is derived (via Old French: Topace and Latin: Topazus) from the Greek Τοπάζιος (Τοpáziοs) or Τοπάζιον (Τοpáziοn), the ancient name of St. John's Island in the Red Sea which was difficult to find and from which a yellow stone (now believed to be chrysolite: yellowish olivine) was mined in ancient times; topaz itself (rather than topazios) was not really known about before the classical era. Pliny says that Topazos is a legendary island in the Red Sea and the mineral "topaz" was first mined there.
The word topaz is related to the Sanskrit word तपस्"tapas" meaning "heat" or "fire", and also to the Hebrew word for "orange" (the fruit): tapooz (תפוז), both of which predate the Greek word.

Pure topaz is colorless and transparent but is usually tinted by impurities; typical topaz is wine, yellow, pale gray, reddish-orange, or blue brown. It can also be made white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent.
Orange topaz, also known as precious topaz, is the traditional November birthstone, the symbol of friendship, and the state gemstone of the US state of Utah.
Imperial topaz is yellow, pink (rare, if natural) or pink-orange. Brazilian Imperial Topaz can often have a bright yellow to deep golden brown hue, sometimes even violet. Many brown or pale topazes are treated to make them bright yellow, gold, pink or violet colored. Some imperial topaz stones can fade on exposure to sunlight for an extended period of time.
Blue topaz is the state gemstone of the US state of Texas. Naturally occurring blue topaz is quite rare. Typically, colorless, gray or pale yellow and blue material is heat treated and irradiated to produce a more desired darker blue.
Mystic topaz is colorless topaz which has been artificially coated giving it the desired rainbow effect

Topaz gemstone meaning

Topaz is one of the twelve breastplate stones of the High Priest referred to in the Book of Exodus. The breastplate stones are considered sacred to twelve mighty angels who guard the gates to Paradise.
Silver Topaz is colorless and untreated. Colorless topaz is often irradiated and heat treated to form blue topaz. Silver Topaz is also called "white topaz".

Silver or White topaz:

  • Increases your awareness of thoughts and deeds and the karmic effects of these
  • Purifies emotions as well as actions
  • Activates cosmic awareness
  • Removes stagnant energy

Topaz meaning

Topaz is a soothing, empathetic stone that will direct energy to the place it is most needed. It heals and energizes. Topaz is a promoter of truth and forgiveness. Use it to find your own path.

How to sell Topaz
When it comes to a question of selling topaz, it has to be treated in one way or other to enhance its color. Since the natural colors of the topaz is not found to be vivid or exciting, makers of jewelry will only use those that have a bright an enhanced look. This is one of the reasons why heat treatment is used to turn a brown or yellow shade of topaz into a pink stone which is thought to be more popular and valuable. Topaz being a very hardy stone, the heat apparently does not damage it in any way.

The genuine topaz in colors of pink, violet and apricot are quite expensive because of the intensity of their color while the treated stone is less expensive and has a wide range of qualities and prices. Traders in gems create various gimmicks when selling topaz and coin names such as "coated topaz" and "mystic topaz" when in fact there are no gems as such but only stones diffused and treated in order to make selling topaz easy. Therefore be careful and ask questions before you decide to buy any topaz jewelry.
One of the easiest ways of selling topaz is by making rings out of the gemstones because rings are always a popular item of jewelry for both men and women. Although the topaz on its own has certain powers, when they are combined with amethyst and made into jewelry, it is supposed to bring out the spiritual energies. It is also said when you wear topaz you have a sound sleep with pleasant dreams and it also wards of evil spirits. Explaining all these curative properties to an interested buyer is another easy way of selling topaz because apart from the beauty of the stone, see how many benefits you can get from wearing topaz?



Monday, January 7, 2013

How to choose precious stones?

Wikipedia Photo
A gemstone or gem (also called a precious or semi-precious stone, a fine gem, or jewel) is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments.[1][ However certain rocks (such as lapis lazuli), or organic materials that are not minerals (such as amber or jet), are also used for jewelry, and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone. Apart from jewelry, from earliest antiquity until the 19th century engraved gems and hardstone carvings such as cups were major luxury art forms; the carvings of Carl Fabergé were the last significant works in this tradition.





Characteristics:
The traditional classification in the West, which goes back to the Ancient Greeks, begins with a distinction between precious and semi-precious stones; similar distinctions are made in other cultures. In modern usage the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent with fine color in their purest forms, except for the colorless diamond, and very hard, with hardnesses of 8–10 on the Mohs scale. Other stones are classified by their color, translucency and hardness. The traditional distinction does not necessarily reflect modern values, for example, while garnets are relatively inexpensive, a green garnet called Tsavorite, can be far more valuable than a mid-quality emerald. Another unscientific term for semi-precious gemstones used in art history and archaeology is hardstone. Use of the terms 'precious' and 'semi-precious' in a commercial context is, arguably, misleading in that it deceptively implies certain stones are intrinsically more valuable than others, which is not the case.
In modern times gemstones are identified by gemologists, who describe gems and their characteristics using technical terminology specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon (C) and rubies of aluminium oxide (Al2O3). Next, many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. For example diamonds, which have a cubic crystal system, are often found as octahedrons.
Gemstones are classified into different groups, species, and varieties. For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Another example are the Emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow), and morganite (pink), which are all varieties of the mineral species beryl.
Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture, and luster. They may exhibit pleochroism or double refraction. They may have luminescence and a distinctive absorption spectrum.
Material or flaws within a stone may be present as inclusions.
Gemstones may also be classified in terms of their "water". This is a recognized grading of the gem's luster and/or transparency and/or "brilliance". Very transparent gems are considered "first water", while "second" or "third water" gems are those of a lesser transparency.
 
Gemstone's Value:
There is no universally accepted grading system for gemstones. Diamonds are graded using a system developed by the Gemological Institute of America (GIA) in the early 1950s. Historically, all gemstones were graded using the naked eye. The GIA system included a major innovation: the introduction of 10x magnification as the standard for grading clarity. Other gemstones are still graded using the naked eye (assuming 20/20 vision).
A mnemonic device, the "four Cs" (color, cut, clarity and carats), has been introduced to help the consumer understand the factors used to grade a diamond. With modification, these categories can be useful in understanding the grading of all gemstones. The four criteria carry different weight depending upon whether they are applied to colored gemstones or to colorless diamond. In diamonds, cut is the primary determinant of value, followed by clarity and color. Diamonds are meant to sparkle, to break down light into its constituent rainbow colors (dispersion), chop it up into bright little pieces (scintillation), and deliver it to the eye (brilliance). In its rough crystalline form, a diamond will do none of these things; it requires proper fashioning and this is called "cut". In gemstones that have color, including colored diamonds, it is the purity and beauty of that color that is the primary determinant of quality.
Physical characteristics that make a colored stone valuable are color, clarity to a lesser extent (emeralds will always have a number of inclusions), cut, unusual optical phenomena within the stone such as color zoning (the uneven distribution of coloring within a gem) and asteria (star effects). The Greeks, for example, greatly valued asteria in gemstones, which were regarded as a powerful love charm, and Helen of Troy was known to have worn star-corundum.
Aside from the diamond, the ruby, sapphire, emerald, pearl (not, strictly speaking, a gemstone) and opal have also been considered to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a precious stone as well, going back to ancient Greece. Even in the last century certain stones such as aquamarine, peridot and cat's eye have been popular and hence been regarded as precious.
Nowadays such a distinction is no longer made by the gemstone trade. Many gemstones are used in even the most expensive jewelry, depending on the brand name of the designer, fashion trends, market supply, treatments, etc. Nevertheless, diamonds, rubies, sapphires and emeralds still have a reputation that exceeds those of other gemstones.
Rare or unusual gemstones, generally meant to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite, axinite, cassiterite, clinohumite and red beryl.
Gem prices can fluctuate heavily (such as those of tanzanite over the years) or can be quite stable (such as those of diamonds). In general per carat prices of larger stones are higher than those of smaller stones, but popularity of certain sizes of stone can affect prices. Typically prices can range from US$1/carat for a normal amethyst to US$20,000–50,000 for a collector's three carat pigeon-blood almost "perfect" ruby.

Cutting:
A few gemstones are used as gems in the crystal or other form in which they are found. Most however, are cut and polished for usage as jewelry. The picture to the right is of a rural, commercial cutting operation in Thailand. This small factory cuts thousands of carats of sapphire annually. The two main classifications are stones cut as smooth, dome shaped stones called cabochons, and stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.
Stones which are opaque such as opal, turquoise, variscite, etc. are commonly cut as cabochons. These gems are designed to show the stone's color or surface properties as in opal and star sapphires. Grinding wheels and polishing agents are used to grind, shape and polish the smooth dome shape of the stones.
Gems which are transparent are normally faceted, a method which shows the optical properties of the stone's interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones. The facets must be cut at the proper angles, which varies depending on the optical properties of the gem. If the angles are too steep or too shallow, the light will pass through and not be reflected back toward the viewer. The faceting machine is used to hold the stone onto a flat lap for cutting and polishing the flat facets. Rarely, some cutters use special curved laps to cut and polish curved facets. (source: wikipedia)



 
 

Wednesday, November 14, 2012

The Biggest Diamonds In The World

The Cullinan diamond is the largest rough gem-quality diamond ever found, at 3,106.75 carats (621.35 g).

The largest polished gem from the stone is named Cullinan I or the Great Star of Africa, and at 530.4 carats (106.1 g)  was the largest polished diamond in the world until the 1985 discovery of the Golden Jubilee Diamond, 545.67 carats (109.13 g), also from the Premier Mine. Cullinan I is now mounted in the head of the Sceptre with the Cross. The second largest gem from the Cullinan stone, Cullinan II or the Lesser Star of Africa, at 317.4 carats (63.5 g), is the fourth largest polished diamond in the world. Both gems are in the Crown Jewels of the United Kingdom.

The Culinan History
The Cullinan  diamond was found by Thomas Evan Powell , a miner who brought it to the surface and gave it to Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, South Africa on January 26, 1905. The stone was named after Sir Thomas Cullinan, the owner of the diamond mine.
Sir William Crookes performed an analysis of the Cullinan diamond before it was cut and mentioned its remarkable clarity, but also a black spot in the middle. The colours around the black spot were very vivid and changed as the analyzer was turned. According to Crookes, this pointed to internal strain. Such strain is not uncommon in diamonds.

The stone was bought by the Transvaal government and presented to King Edward VII on his birthday. It was cut into three large parts by Asscher Brothers of Amsterdam, and eventually into 9 large gem-quality stones and a number of smaller fragments. At the time, technology had not yet evolved to guarantee quality of the modern standard, and cutting the diamond was considered difficult and risky. In order to enable Asscher to cut the diamond in one blow, an incision was made, half an inch deep. Then, a specifically designed knife was placed in the incision and the diamond was split in one heavy blow. The diamond split through a defective spot, which was shared in both halves of the diamond

10 Biggest Diamond in The World



Wednesday, October 24, 2012

The most popular diamonds in the world

Akbar Shah Diamond
The rulers of the Mughal dynasty had a passion for chronicling their reign and almost every emperor in that lineage commissioned lavishly illustrated biographies. These documents have proved to be invaluable resources for later historians who have been able to use them to reconstruct the social and political events during the lives and times of the Mughal emperors.
These meticulously recorded volumes have been especially valuable in reconstructing the story of the historic Akbar Shah diamond. This fabulous gem, which once weighed 116 carats, is said to have borne two inscriptions in Persian. One referred to its first owner, Emperor Jahangir. According to the etching, the stone found its way into the Imperial Treasury of the emperor in 1619. A possible allusion to this can be found in the Tuzuk-i-Jahangiri(Memoirs of Jahangir). These records, either written in Jahangir's own hand or dictated to a scribe, cover the period of his reign(1605–27) and illustrate his glamorous lifestyle. Of his sojourn in Gujarat, it is recorded: On Friday the 5th, Bahram, son of Jahangir Quli Khan, came from the province of Bihar, and had the good fortunes to pay his respects. He laid before me some diamonds he had obtained from the mines at Kokhra.

It is likely that the Akbar Shah was among the array of diamonds that were presented to Jahangir. It is interesting to note that the memoirs make a mention of diamond deposits from the mine at Kokhra (present day Khukra, 64 km west of Ranchi)in the eastern state of Bihar. Apparently, these were not from a mine at all, but from a river bed that was fertile with diamonds. Though Jahangir's memoirs give a description of how large diamonds were also mined from this source, this area has rarely been given due credit by the diamond mining industry. In fact, it is hardly ever mentioned as a diamond rich region in India.

The second inscription on the Akbar Shah confirms that it officially became a part of Shah Jahan's treasury in 1629. It is widely believed by historians that this celebrated gem was set as one of the eyes of the peacock in the fabulous Peacock Throne. However, other scholars suggest the possibility of it being the dazzling diamonds encircled by emeralds and rubies, suspended opposite the throne. But there are yet other authorities who feel that the suspended gem was the Shah diamond.

The Allnatt Diamond is a diamond measuring 101.29 carats (20.258 g) with a cushion cut, rated in color as Fancy Vivid Yellow by the Gemological Institute of America. This diamond is named after one of its holders, Major Alfred Ernest Allnatt, a soldier, sportsman, art patron and benefactor. While it is not known precisely where the Allnatt originated, many experts believe that it was probably found in what is now known as the De Beers Premier Diamond Mine.
The Allnatt's origins are unknown prior to Major Allnatt's purchasing of the diamond in the early 1950s. After purchasing the diamond, he commissioned Cartier to make a setting for it. The final setting was a platinum flower with five petals, a stem and two leaves, all set with diamonds. The Allnatt was resold at auction in May 1996 by Christie's in Geneva for $3,043,496 US. At the time of its sale the Allnatt was 102.07 carats (20.41 g). and was graded Fancy Intense Yellow. After being sold to the SIBA Corporation, the diamond was re-cut to its current weight and the intensity was upgraded as a result.
The Allnatt was displayed as part of the Smithsonian's "The Splendor of Diamonds" exhibit, alongside The De Beers Millennium Star and The Heart of Eternity.

Cora Sun Drop Diamond
The Cora Sun-Drop Diamond is the largest yellow pear-shaped diamond known, weighing 110.3 carats (22.1 g). Being sold for $10.9 million it has set a world record for a yellow diamond.
The Sun-Drop has a very short history. It was found in South Africa in 2010 within a kimberlite pipe. Tests show that the diamond was formed from 1 to 3 billion years ago. After that, on 24 February 2011, it was kept in The Vault of the London Natural History Museum together with many other precious stones, such as the Duke of Devonshire Emerald and the Aurora Pyramid of Hope, where it stayed for six months. In November 2011, it was sold at an auction in Geneva for just over $10.9 million.[2] The stone was cut and owned by the diamond manufacturing company Cora International, based in New York. It was sold at the auction by Sotheby's Magnificent Jewels. The Sun-Drop was bought by a telephone bidder who decided to remain anonymous. Including commission and taxes the buyer paid $12.36 million. The pre-sale estimate was from 11 to 15 million dollars. "It sold for a record for a yellow diamond ... It was exactly within our expectation for this spectacular stone," said Mr Bennett, an auctioneer.

Saturday, October 13, 2012

Diamond Planet Has Found....!

Andrew Fazekas
Published October 11, 2012

The universe just got a bit richer with the discovery of an apparent diamond-rich planet orbiting a nearby star.
Dubbed 55 Cancri e, the rocky world is only twice the size of Earth but has eight times its mass—classifying it as a "super Earth," a new study says. First detected crossing in front of its parent star in 2011, the close-in planet orbits its star in only 18 hours. As a result, surface temperatures reach an uninhabitable 3,900 degrees Fahrenheit (2,150 degrees Celsius)—which, along with carbon, make perfect conditions for creating diamonds.
NASA's Spitzer Space Telescope collected data on the planet's orbital distance and mass, and resulting computer models created a picture of 55 Cancri e's chemical makeup.
"Science fiction has dreamed of diamond planets for many years, so it's amazing that we finally have evidence of its existence in the real universe," said study leader Nikku Madhusudhan, a postdoctoral researcher at Yale University.
"It's the first time we know of such an exotic planet that we think was born mostly of carbon—which really makes this a fundamental game-changer in our understanding of what's possible in planetary chemistry."
At only 40 light-years away, in the northern constellation Cancer, the gemlike planet sits relatively near Earth. In dark skies, 55 Cancri e's host star is clearly visible to the naked eye. (See gem pictures.)

Diamond Planet Has Odd Chemistry
The new models fit with previous studies that showed 55 Cancri e's parent star was abundant in carbon—much more so than our sun.
"If we make the assumption that the star and its surrounding planets are all born from the same primordial disk of material, then it makes sense that the entire planetary system would be carbon rich," said Madhusudhan, whose study will appear in an upcoming issue of the journal Astrophysical Journal Letters.
Princeton astronomer David Spergel believes the diamond-planet find probably represents the first discovery of a whole new class of planets whose chemistry has never been encountered. (Related: "'Diamond Planets' Hint at Dazzling Promise of Other Worlds.")
"Unlike our solar system, which is dominated by oxygen and silicates, this planetary system is filled with carbon," said Spergel, who was not involved in the new study.
"While it's still unknown exactly what implication this will have on our understanding of evolution of planetary systems," he said, "there's no doubt it is an important step towards understanding the full diversity of planets."

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