Peridot (pronounced /ˈpɛrɪdɒt/ or /ˈpɛrɪdoʊ/) is gem-quality forsteritic olivine. The chemical composition of peridot is (Mg, Fe)2SiO4, with Mg in greater quantities than Fe.
The origin of the name "peridot" is uncertain. The Oxford English Dictionary suggests an alteration of Anglo-Norman pedoretés (classical Latin paederot-), a kind of opal, rather than the Arabic word faridat, meaning "gem".
Olivine in general is a very abundant mineral, but gem quality peridot is rather rare.
Peridot is one of the few gemstones that occur in only one color: basically an olive green. The intensity and tint of the green however depends on how much iron is contained in the crystal structure, so the color of individual peridot gems can vary from yellow-green through olive green to brownish green. The most valuable is considered a dark-olive green color.
Peridot crystals have been collected from some Pallasite meteorites. A famous Pallasite was offered for auction in April 2008 with a requested price of close to $ 3 million at Bonhams, but remained unsold. Peridot is the only gemstone found in meteorites.
Peridot olivine is the birthstone for August. It is sometimes mistaken for emeralds and other green gems. In fact notable gemologist George Frederick Kunz discussed the confusion between emeralds and peridots in many church treasures, notably the "Three Magi" treasure in the Dom of Cologne, Germany.
The most common colour of aventurine is green, but it may also be orange, brown, yellow, blue, or gray. Chrome-bearing fuchsite (a variety of muscovite mica) is the classic inclusion, and gives a silvery green or blue sheen. Oranges and browns are attributed to hematite or goethite. Because aventurine is a rock, its physical properties vary: its specific gravity may lie between 2.64-2.69 and its hardness is somewhat lower than single-crystal quartz at around 6.5.
Aventurine feldspar or sunstone can be confused with orange and red aventurine quartzite, although the former is generally of a higher transparency. Aventurine is often banded and an overabundance of fuchsite may render it opaque, in which case it may be mistaken for malachite at first glance.
The name aventurine derives from the Italian "a ventura" meaning "by chance". This is an allusion to the lucky discovery of aventurine glass or goldstone at some point in the 18th century. Although it was known first, goldstone is now a common imitation of aventurine and sunstone. Goldstone is distinguished visually from the latter two minerals by its coarse flecks of copper, dispersed within the glass in an unnaturally uniform manner. It is usually a golden brown, but may also be found in blue or green.
The majority of green and blue-green aventurine originates in India (particularly in the vicinity of Mysore and Madras) where it is employed by prolific artisans. Creamy white, gray and orange material is found in Chile, Spain and Russia. Most material is carved into beads and figurines with only the finer examples fashioned into cabochons, later being set into jewellery.
Main markets for aventurine are landscape stone, building stone, aquaria, monuments, and jewellery.
The Star of India is a 563.35 carat (112.67 g) star sapphire, probably the largest such gem in the world. It is almost flawless and unusual in that it has stars on both sides of the stone. The greyish blue gem was mined in Sri Lanka and is now kept in the American Museum of Natural History in New York City.
The milky quality of the stone is caused by the traces of the mineral rutile, which is also responsible for the star effect, known as the effect of asterism. The tiny fibers of the mineral, aligned in a three-fold pattern within the gem, reflect incoming light into the star pattern.
History
In 1900, wealthy financier J.P. Morgan donated the Star of India to the American Museum of Natural History on Central Park West in Manhattan. On October 29, 1964, the famous golf-ball-sized stone was stolen, along with several other stones, including the Eagle Diamond and the de Long Ruby. The thieves unlocked a bathroom window during museum open hours, climbed in that night, and found that the sapphire was the only gem in the collection protected by an alarm — and the battery for that was dead. So they raked up the stones and fled the same way they came in. The stones were valued at more than $400,000. Within two days, the notorious cat burglar, smuggler, and one-time surfing champion, Jack Murphy (also known as Murph the Surf), was arrested along with two accomplices, later receiving a three-year sentence. Some months later, the uninsured Star of India was recovered in a locker in a Miami bus station. While most of the other gems were also found, the Eagle Diamond was never seen again.
From the gorgeous 5.4 mm 0.7 ct. round fancy yellow diamond and the rare 0.40 carat princess cut fine yellow fancy diamond with SI2 clarity, to the elegant 4 carat yellow diamond with I4 clarity, we are more than certain you will find just the yellow diamond you have been looking for, at a value that simply can't be beat!
The Star of the South, also known as Estrela do Sul, is a diamond found in Brazil in 1853. The diamond is cut into a cushion shape and weighs 128.48 carats (25.70 g). The Star of the South is graded as a type IIa diamond, with a colour grading of light pinkish-brown and a clarity of VS2. At the time of discovery, the diamond weighed 254.5 carats (50.9 g). It has passed through the hands of many owners, and its last known purchase was by Cartier store, when it was sold by Rustomjee Jamsetjee of Mumbai. The light reflected by the diamond is white, and the refracted light is of a rose tint. This gives the diamond its light pinkish-brown hue.
The diamond was found by a slave girl in 1853, at the Bagagem Diamond Mines in Brazil. It was handed over to her master, Casimiro de Tal, who rewarded her for finding the diamond by granting her freedom and a pension for life. Casimiro de Tal later sold it for £3,000, a price far lower than its actual value. The buyer deposited the diamond at the Bank of Rio de Janeiro for £30,000.
The uncut diamond was passed through the hands of several buyers, until it was bought by Coster’s Establishment of Amsterdam for £35,000. It was then cut into an oval cushion shape by a cutter called Voorsanger of Coster’s Establishment, at a cost of £500.
It was purchased by Halphen and Associates of Paris, a syndicate of diamond merchants led by Messrs. Halphen, who named it Estrela do Sul, or Star of the South. The syndicate exhibited the diamond 1862 at the London Exhibition, and again 1867 at the Paris Exhibition. On both occasions, the Star of the South received considerable attention. The diamond was later sent to a diamond dealing house in India, where negotiations were carried out to sell it to a Maharajah for a price of £110,000. However, this deal was not successful and the diamond was returned to Halphen and Associates.
During the diamond’s stay in India, Prince Mulhar Rao of the royal family of Gaekwad got to know about the stone. He instructed E. H. Dresden of London to purchase the diamond, who purchased it from Halphen and Associates for £80,000 on behalf of the prince. The Star of the South was in the possession of the Gaekwad family for several years. It was later mounted on a necklace along with the 78.5 carats (15.7 g) English Dresden diamond. In 1934, Prince Mulhar Rao’s son had told Robert M. Shipley, an American gemologist about this. In 1948, the Maharani Sita Devi of Baroda, was photographed wearing the necklace at her husband Maharajah Pratapsinh's birthday party.
The Star of the South was later purchased by Rustomjee Jamsetjee of Mumbai, who sold it to Cartier in 2002.
The Florentine Diamond is a lost diamond of Indian origin. It is light yellow in colour with very slight green overtones. It is cut in the form of an irregular (although very intricate) nine-sided 126-facet double rose cut, with a weight of 137.27 carats (27.454 g). The stone is also known as the Tuscan, the Tuscany Diamond, the Grand Duke of Tuscany, the Austrian Diamond and the Austrian Yellow Diamond.
The stone's origins are disputed. Reportedly, it has been cut by Lodewyk van Berken for Charles the Bold, Duke of Burgundy. Charles is said to have been wearing it when he fell in the Battle of Morat on June 22, 1476. A peasant or foot soldier found it on the Duke's person and sold it for a florin, thinking it was glass. The new owner Bartholomew May, a citizen of Berne, sold it to the Genoese, who sold it in turn to Ludovico Sforza. By way of the Fuggers it came into the Medici treasury at Florence. Pope Julius II is also named as one of its owners.
Another version of the stone's early history is that the rough stone was acquired in the late 1500s from the King of Vijayanagar in southern India by the Portuguese Governor of Goa, Ludovico Castro, Count of Montesanto, after the king's defeat by Portuguese troops. The crystal was deposited with the Jesuits in Rome until, after lengthy negotiations, Ferdinando I de' Medici, Grand Duke of Tuscany succeeded in buying it from the Castro-Noronha family for 35,000 Portuguese scudi crocati.
Duke Ferdinand's son, Cosimo II, finally entrusted his father's purchase to a cutter, Pompeo Studentoli, a Venetian working in Florence. The finished gem was delivered on October 10, 1615. An inventory drawn up on Cosimo's death confirms the acquisition of the rough diamond by Ferdinand and describes the gem as 'faceted on both sides and encircled by a diamond encrusted band'.
Documented history begins when Jean Baptiste Tavernier, the French jeweller and traveller saw the stone among the possessions of Ferdinando II de' Medici, Grand Duke of Tuscany in 1657. It then passed into the hands of the Habsburgs when the last of the Medicis died through the marriage of Francis III Stephan of Lorraine to Empress Maria Theresa of Austria and was placed in the Habsburg Crown Jewels in the Hofburg in Vienna. At the time it was valued at $750,000.
After the fall of the Austrian Empire during World War I, the stone was taken by the Imperial Family into exile in Switzerland. The stone was stolen some time after 1918 by a person close to the family and taken to South America with other gems of the Crown Jewels. After this, it was rumoured that the diamond was brought into the United States in the 1920's and was recut and sold.
The Noor-ol-Ain is the principle diamond mounted in a tiara of the same name made for Iranian Empress Farah Pahlavi's wedding to Shah Mohammad Reza Pahlavi in 1958. The Diamond is believed to have been recovered from the Golconda mines in India and was brought into the Iranian Imperial collection after the conquest of that country by Nader Shah Afshar in the 18th century.
It is one of the largest pink diamonds in the world and is believed to have once formed part of an even larger gem. That larger diamond is thought to have been cut in two, with one section becoming the Noor-ol-Ain and the other the Darya-ye Noor diamond. Both of these pieces are currently part of the Iranian Crown Jewels.
Noor-ol-Ain translated from Persian means the light of the eye.
The Darya-ye Noor "Sea of Light", "River of Light" or "Ocean of Light"; also spelled Darya-i-Noor, Darya-e Noor and Darya-i-Nur is one of the largest diamonds in the world, weighing an estimated 182 carats (36 g). Its colour, pale pink, is one of the rarest to be found in diamonds. The Darya-ye Noor presently forms part of the Iranian Crown Jewels and is on display at the Central Bank of Iran in Tehran.
This diamond, like the Kohinoor, was mined at the Golconda mines, more specifically Paritala-Kollur Mine in Andhra Pradesh, India[2]. It found its way into the possession of the mughal emperors.
In 1739, Nader Shah of Iran invaded India and sacked Delhi; the plunder he garnered from the Mughal treasury included the Darya-i-noor, in addition to the Kohinoor and the Peacock throne. All of these treasures were carried to Iran by Nader Shah and the Darya-i-noor has remained there ever since.
After Nader Shah's death, the Darya-ye Noor was inherited by his grandson, Shahrokh Mirza. It then passed into the possession of Alam Khan Khozeimeh, and later, of Lotf Ali Khan Zand, a member of Iran's Zand dynasty. Agha Mohammad Khan, founder of Qajar dynasty, defeated the Zands, and thus the Darya-e-noor came into the possession of the Qajars. Fath Ali Shah Qajar had his name inscribed on one facet of the diamond. Later, Nasser-al-Din Shah Qajar often wore it on an armband. He apparently believed that this diamond had been one adorning the crown of Cyrus . When armbands fell from royal fashion, he wore the diamond as a brooch. On occasion, the gem would be left in the care of high personages of the land, as a sign of honor. It was eventually kept hidden in the Golestan Palace treasury museum until Mozzafar-al-Din Shah Qajar's time -- this monarch wore it as a hat decoration while visiting Europe in 1902. Reza Shah, founder of the Pahlavi dynasty, wore the diamond as a decoration on his military hat during his coronation in 1926, and it was used in Mohammad Reza Shah Pahlavi's coronation ceremony in 1967.
Possible association
In 1965, a Canadian team conducting research on the Iranian Crown Jewels concluded that the Darya-e-Noor may well have been part of a large pink diamond that had been studded in the throne of the mughal emperor Shah Jahan, and had been described in the journal of the French jeweller Tavernier in 1642, who called it the "Diamanta Grande Table". This diamond may have been cut into two pieces; the larger part is the Darya-e-noor ("Sea of Light"); the smaller part is believed to be the 60 carats (12 g) Noor-ol-Ein diamond, presently studded in a tiara also in Iranian Imperial collection.
The Kōh-i Nūr (Telugu: కోహినూరు; Hindi: कोहिनूर, Persian/Urdu: کوہ نور, Bangla: কহিনূর) "Mountain of Light"; also spelled Kohinoor, Koh-e Noor or Koh-i-Nur) is a 105 carat (21.6 g) diamond that was once the largest known diamond in the world. The Kohinoor originated at Golconda in the state of Andhra Pradesh in India, belonged to various Mughal and Persian rulers who fought bitterly over it at various points in history, and seized as a spoil of war, was finally stolen by the British and became part of the British Crown Jewels when British Prime Minister Benjamin Disraeli proclaimed Queen Victoria Empress of India in 1877.
Like all significant jewels, the Kohinoor has its share of legends. It is reputed to bring misfortune or death to any male who wears or owns it. Conversely, it is reputed to bring good luck to female owners. According to another legend, whoever owns the Koh-i-Noor rules the world
Origins and early history
The origins of the diamond are unclear. Many early stories of great diamonds in southern India exist, but it is hard to establish which one was the Koh-i-noor. According to some sources, the Koh-i-noor was originally found more than 5000 years ago, and is mentioned in ancient Sanskrit writings under the name Syamantaka. According to some Hindu mythological accounts. Krishna himself obtained the diamond from Jambavantha, whose daughter Jambavati later married Krishna. The legend says that the diamond was from the Sun God to Satrajith (father of Satyabhama)which produces 1000 kg of gold daily. Krishna got the blame of stealing the diamond from Satrajith's brother who is actually killed by a lion which in turn was killed by Jambavantha.
Historical evidence suggests that the Kohinoor originated in the Golconda kingdom, in the south Indian state of Andhra Pradesh, one of the world's earliest diamond producing regions. This region was the only known source for diamonds until 1730 when diamonds were discovered in Brazil. The term "Golconda" diamond has come to define diamonds of the finest white color, clarity and transparency. They are very rare and highly sought after.
South Indian folklore is definite in claiming a local origin for the stone. It is likely that the diamond was mined in the Kollur mines near the village Paritala in the present day Krishna district of Andhra Pradesh. The diamond became the property of Kakatiya kings. The Khilji dynasty at Delhi ended in 1320 A.D. and Ghiyas ud din Tughluq Shah I ascended the Delhi throne. Tughlaq sent his son Ulugh Khan in 1323 to defeat the Kakatiya king Prataparudra. Ulugh Khan’s raid was repulsed but he returned in a month with a larger and determined army. The unprepared army of Kakatiya was defeated. The loot, plunder and destruction of Orugallu(present day Warangal), the capital of Kakatiya Kingdom, continued for months. Loads of gold, diamonds, pearls and ivory were carried away to Delhi on elephants, horses and camels. The Koh-i-noor diamond was part of the bounty. From then onwards, the stone passed through the hands of successive rulers of the Delhi sultanate, finally passing to Babur, the first Mughal emperor, in 1526.
The first confirmed note historically mentioning the Koh-i-noor by an identifiable name dates from 1526. Babur mentions in his memoirs, the Baburnama, that the stone had belonged to an un-named Rajah of Malwa in 1294. Babur held the stone's value to be such as to feed the whole world for two days. The Baburnama recounts how Rajah of Malwa was compelled to yield his prized possession to Ala ud din Khilji; it was then owned by a succession of dynasties that ruled the Delhi sultanate, finally coming into the possession of Babur himself in 1526, following his victory over the last ruler of that kingdom. However, the Baburnama was written c.1526-30; Babur's source for this information is unknown, and he may have been recounting the hearsay of his day. He did not at that time call the stone by its present name, but despite some debate about the identity of 'Babur's Diamond' it seems likely that it was the stone which later became known as Koh-i-noor.
Both Babur and Humayun mention very clearly in their memoirs the origins of 'Babur's Diamond'. This diamond was with the Kachhwaha rulers of Gwalior and then inherited by the Tomara line. The last of Tomaras, Vikramaditya, was defeated by Sikandar Lodi, Sultan of Delhi and became Delhi sultanate pensioner and resided in Delhi. On the defeat of Lodis and replacement by Mughals, his house was looted by the mughals and Prince Humayun interceded and restored his property even allowing him to leave Delhi and take refuge in Mewar at Chittaur. In return for Humayun's kindness, one of the diamonds, most likely the Koh-i-noor, in possession of Prince Vikaramaditya was given to Humayun in gratitude. Humayun had much bad luck throughout his life. Sher Shah Suri, who defeated Humayun, died in the flames of a burst cannon. His son Jalal Khan was murdered by his brother-in-law, who was overthrown by his minister, who in turn lost the empire of India by the unlucky accident of getting hit in the eye at stroke of victory. Humayun's son, Akbar, never kept the diamond with himself and later only Shah Jahan took it out of his treasury. Akbar's grandson, Shah Jahan was overthrown by his son, Aurangazeb, who orchestrated the death and murder of his three brothers.
The Aurora Pyramid of Hope is the most comprehensive natural color diamond collection in the world[1]. It was on public display at the American Museum of Natural History in New York from 1989 to 2005 in the Morgan Hall of Gems. Aurora Pyramid of Hope was the centerpiece for the 1998 exhibition The Nature of Diamonds organized by the American Museum of Natural History which toured Japan, Canada and the U.S. In 2005 Aurora Pyramid of Hope was invited to participate in the exhibition Diamonds organized by The Natural History Museum of London. At that time 36 new specimens were added to the original 260 diamonds. Today Aurora Pyramid of Hope consists of 296 diamonds weighing a total of 267.45 carats (53.49 g).
All the colors of the spectrum that diamonds exist in are represented in various shapes, saturations and modifiers including blue diamonds, pink diamonds, red diamonds, green diamonds, orange diamonds, purple diamonds, violet diamonds, yellow diamonds, olive diamonds and brown diamonds. Also represented are color changing chameleon diamonds. Aurora Pyramid of Hope was put together by Alan Bronstein and Harry Rodman over 25 years.
Aurora Pyramid of Hope is currently on display at The Natural History Museum of London.
The Aurora Butterfly of Peace diamond collection is an artwork consisting of 240 natural, fancy colored diamonds weighing a combined total of 167 carats (33 g). This diamond mosaic, designed as a butterfly, was created over a period of 12 years by Alan Bronstein and Harry Rodman. The diamonds were collected and assembled one stone at a time, and today serve as a tribute to the universally beloved butterfly. The Aurora Butterfly of Peace was conceived by the artists as an eternal icon of love, beauty, energy, nature, peace. It symbolizes a spiritual connection to earth for all mankind. From November 2004 thru July 2005, the Butterfly of Peace was exhibited in the National Gem Collection Gallery at the Smithsonian Institution in Washington D.C.
A smaller version of the Butterfly of Peace was displayed at The Houston Museum of Natural Science from June 1994 thru March 1996. The Aurora Butterfly of Peace was on display from May 25th to July 30, 2008 at the Museum of the Gemological Institute of America (GIA), to help launch “The Facets of the GIA” exhibit, which showcases the prominent role of the Institute in the world of gemology.
Two research studies involving the Butterfly of Peace have resulted in new scientific breakthroughs about fluorescence and phosphorescence in fancy colored diamonds. The amazing phenomena of fluorescence can be seen as a skeletal pattern of glowing colors when the diamonds are exposed to ultraviolet light. There are rare and unusual color diamonds that make up the design including purples from Russia, blues and oranges from South Africa, lime greens from Brazil, violets and dozens of pinks from the Argyle Mine in Australia."
Ashberg Diamond is an amber-colored, cushion-shaped diamond weighing 102.48 carats (20.50 g), was formerly part of the Russian Crown Jewels.
This is believed to be mined in South Africa, because of its characteristics
The Amsterdam Diamond is a black diamond weighing 33.74 carats (6.75 g), and has 42 facets. It is in a pear shape, and cut from a 55.85 carats (11.17 g) rough. It was sold in 2001 for $352,000, thus making it the highest price paid for a black diamond at auction.
The Amarillo Starlight is the largest diamond found by a park visitor in the Crater of Diamonds State Park in Arkansas since 1972, when it was established as a state park. The Amarillo Starlight was found by W. W. Johnson of Amarillo, Texas in 1975 while he was vacationing at the park with his family. When unearthed, it was a 16.37 carats (3.27 g) white diamond, but it has since been cut into a 7.54 carats (1,510 mg) marquise shape. Its price is estimated between $150,000 and $175,000.
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 plhjugfryulrgyulgrkugruyeqguykr 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.
Aquamarine (Lat. aqua marina, "water of the sea") is a gemstone-quality transparent variety of beryl, having a delicate blue or turquoise color, suggestive of the tint of seawater. It is closely related to the gem emerald. Colors vary, and in addition to blue, yellow beryl (heliodor), rose pink beryl (morganite), red beryl (formerly bixbite), and white beryl (goshenite) are also to be found.
Composition
Aquamarine is a beryl with a hexagonal crystal structure and a chemical formula of Be3Al2(SiO3)6, a beryllium aluminium silicate mineral. It has a specific gravity of 2.68 to 2.74 and a Mohs hardness of from 7.5 to 8. Aquamarine typically is on the low end of the specific gravity range, normally at less than 2.7. The pink variety exhibits a high specific gravity of around 2.8. Refractive indices range around 1.57 to 1.58.
Locations of deposits
It occurs at most localities which yield ordinary beryl, some of the finest coming from Russia. The gem-gravel placer deposits of Sri Lanka contain aquamarine. Clear yellow beryl, such as occurs in Brazil, is sometimes called aquamarine chrysolite. When corundum presents the bluish tint of typical aquamarine, it is often termed Oriental aquamarine.
In the United States, aquamarines can be found at the summit of Mt. Antero in the Sawatch Range in central Colorado. In Wyoming, aquamarine has been discovered in the Big Horn mountains, near Powder River Pass. In Brazil, there are mines in the states of Minas Gerais, Espírito Santo and Bahia. Colombia, Zambia, Madagascar, Malawi, Tanzania and Kenya also produce aquamarine.
The biggest aquamarine ever mined was found at the city of Marambaia, Minas Gerais, Brazil, in 1910. It weighed over 110 kg, and its dimensions were 48.5 cm long and 42 cm in diameter
Perfection is to be found in this stone: a blue diamond sold at $7.98 million, establishing a new record as the most expensive gemstone per carat bought at auction. The buyer is Moussaieff Jewellers of London, a specialist in rare stones and the stone was sold by a private Asian collector at a Sotheby's auction in Hong Kong.
The 8 minute bidding for the emerald-cut 6.04 carat diamond resulted in its sale for $1.32 million per carat, far higher than the previous record of $926,000 per carat, set by a red emerald-cut diamond, Hancock Red, sold in New York two decades ago.
A carat means 0.2 g. The world's biggest blue diamond is the 45.52-carat Hope Diamond. Still, this is the biggest and rarest vivid blue diamond on offer since Sotheby's Hong Kong auction in 2004, when a similar stone was sold for $ 4.2 million. The rare, vivid blue color of the diamond is said to be induced by the presence of an element called boron in its crystal structure.
"The bidding was fast and furious and you know it's not as if one could go out and buy another one," said Quek Chin Yeow, head of Jewellery Asia at Sotheby's.
"It's as rare as getting a Renoir or a wonderful Rothko. When you look at the stone, it sings. The blue sings. The cutting is wonderful. It has just got such beauty and I mean the fact that it's flawless, it's just an amazing " he said.
The demand for colored diamonds among jewellery collectors is high in Europe, the United States and Asia and blue diamonds come mainly from the Premier Mine in South Africa.
The total sale in Hong Kong's Monday auction was estimated at $ 40.8 million.
An emerald rope-necklace owned by the American songwriter and lyricist Irving Berlin also sold for $2.64 million, including commission, at yesterday's sale.
For all the beauty and complexity of a well-cut diamond, they are the simplest of gemstones in the chemical sense: pure carbon, the same as the graphite in a pencil. They are formed under intense heat and pressure deep within the earth, and are forced to the surface by geological events.Diamonds are harder than any other material on earth, earning them a 10 on the Mohs' scale of hardness. They can only be cut by other diamonds. Their hardness and other special qualities, such as how they refract light, allow them to be cut into the amazing gems we know today.
Diamonds have been at the heart of myth and legend since their discovery. Medieval knights wore them uncut on their armor in the belief that they could make a person invincible, a myth no doubt related to the stone's hardness. There are legends of a diamond that could reveal the guilt or innocence of a person. Diamonds could also drive away the devil, and in the days when gems were believed to cure disease and ill fortune, diamonds were thought to amplify the magical powers of other stones a person wore.
ITEM #: 17783937
$6899.00
While diamonds are the hardest minerals, they still require some care to keep them looking their best and to protect them from loss or damage.
A regular professional cleaning is recommended. Diamond jewelry can easily acquire a buildup of dirt, makeup and other materials that diminish its brightness, especially if it's worn every day. Many jewelers, including Zales, offer professional cleaning. Avoid using ultrasonic cleaners if your diamond has a serious crack or inclusion. The vibrations of these cleaners can enlarge such flaws.
ITEM #: 17786302
$31399.00
In jewelry pieces with more than one diamond, the carats may be described in terms of total carat weight (TW). This is the combined total weight of all the stones in the piece.
Diamonds can range in size from a fraction of a carat to several carats. Given the rarity of large stones, however, the price increases rapidly with size; therefore, a single 2-carat diamond will cost much more than two 1-carat diamonds. Very large diamonds with good color and clarity are very rare.
Because round brilliant cuts follow exact standards, you can make a good estimate of the carat weight of the stone based on the stone's diameter. The following chart compares the relative sizes of stones and describes how much a round brilliant diamond of a certain size is likely to weigh. This method doesn't work as well for other cuts or shapes, though, since some are thicker or thinner than others; nor does this chart apply to colored gemstones, which have a different density from diamonds.
In the strictest definition of the term, "cut" is not the same thing as "shape" - for example, the most popular cut for a diamond is the round brilliant cut, but there are also round Swiss cuts, round Old European cuts, and round 144-facet cuts. For the most part, however, the terms are used interchangeably, including on this site.The 58-facet round brilliant cut is the most popular because of its fire and brilliance. (These terms describe the intensity of the color and brightness of the light one sees in a diamond.) This is achieved by cutting the stone to very exacting mathematically-determined proportions so as much light as possible is reflected out the top of the diamond.
1 CT. Certified Radiant-Cut Diamond Solitaire Ring in Platinum (G-H/VS2)
ITEM #: 17783648
$24499.00
It is very common for diamonds to be formed with slight imperfections. These are known as "inclusions" and can come in many forms, including tiny white points, dark dots, or feathery cracks. The fewer inclusions, the more the stone is worth. A diamond's clarity ranking is determined by the number, size, type and placement of the inclusions. The following is the GIA clarity scale, along with corresponding definitions for different clarity grades, which is very commonly used in the United States:
FL
FLAWLESS
Free from all inclusions orblemishes at 10x magnification.
IF
INTERNALLY FLAWLESS
No inclusions visible at 10x,insignificant surface blemishes.
VVS1VVS2VS1VS2
MINOR INCLUSIONS
Difficult to see face-up at 10x.
SI1SI2
NOTICEABLE INCLUSIONS
Easy to see at 10x.
I1I2I3
OBVIOUS INCLUSIONS
Easily visible to unaided eye.
ITEM #: 16825051
Color is only one of the four C's so even when a stone has a visible tint, such as K or above, it can still be very lovely if it has good clarity and cut. How the diamond is set can make a difference, too; you might not want to put a truly colorless diamond in a yellow gold setting since the yellow color will reflect in the stone. On the other hand, a slightly yellow stone will appear whiter in a yellow gold setting.
The following is the GIA color scale, which is very commonly used in the United States:
Every diamond is different, incorporating a complex constellation of factors that determine the rarity of each stone. Although gemologists train for years to master the art and science of diamond appraisal, with a little basic instruction, anyone can learn how to read an appraisal and compare the grades of different stones.
Diamonds are graded using a system that judges the stone on its color, clarity, cut and carat weight - commonly known as the "four C's." Diamonds of uncommonly high quality and size are often sold as "certified diamonds" and come with a certificate that proves the stone's value. Even non-certified diamonds, however, should be evaluated using the four C's to help determine cost.ITEM #: 17693417
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Topaz, and especially blue topaz, has grown in popularity over the years. The "pure" topaz color is yellow, and was often confused with chrysolite, the yellow variety of peridot. However, the use of distinct colors has helped topaz come into its own. Blue topaz in particular is popular in jewelry today. It has a watery blue similar to aquamarine, but often without the green overtones, and its hardness and good clarity make it an excellent gem. The blue color is often enhanced through heat-treatment and irradiation.
Topaz was believed to have incredible medicinal powers in the Middle Ages, even against the plague. For a healthy individual, it brought about a pleasant disposition and patience and was a symbol of fidelity and love.
Blue topaz is December's birthstone.
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Along with the emerald and sapphire, ruby is one of the most prized colored gem available. The main quality of the ruby is its bright red color. The best color usually comes from Burma and is very costly; stones from Thailand are darker but clearer and much more common. Only red stones are called rubies. If the color is too light to be called red, it is a pink sapphire.
Corundum, the main material of ruby, is the second-hardest material known after diamond. Inclusions and flaws are fairly common, and many rubies are treated to enhance their color. In general, one should look for a bright red stone with as few inclusions as possible. Synthetic rubies offer good color, clarity and size, and are more affordable.
Corundum (aluminum oxide), the same family as sapphire, with the color coming from chromium. Mohs' hardness rating of 9.
Lab-Created Ruby Cathedral Ring in 10K Gold with Diamond Accents
Oval Ruby Fashion Ring in 14K Gold with Diamond Accents
Tourmaline is reputed to have a powerful positive influence on love and friendship. With a Mohs' hardness rating of 7 to 7.5, tourmaline is a very durable and easy to maintain gemstone perfect for everyday wear.
Any color to multi-colored to opaque black
Primarily composed of sodium and boro-silicate hydroxide. Mohs' hardness rating of 7 to 7.5.
Iridescent
Composed of nacre, the same substance as pearls
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Almost all emeralds have inclusions in them; the fewer these impurities, the rarer and costlier the stone. Because of these inclusions, emeralds can be brittle, so protect your emeralds from hard contact when you wear them. Ultrasonic cleaners, which use vibrations to remove dirt and buildup, can be dangerous to heavily included emeralds. Natural emeralds also tend to have thin scratches on the surface. A layer of wax or oil is usually applied to smooth out their appearance and enhance their color. This layer may have to be replaced professionally every few years.
It was believed to sharpen wits, bring wealth, foretell the future, tell whether a lover was lying and cure all types of evil and illness.
Emerald is the birthstone of May.
Green to bluish green.
The most valuable form of beryl and one of the world's most precious gems. Color comes from chromium. Mohs' hardness rating of 8, but sometimes brittle.
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Yellow to yellow-orange to brown
A type of quartz. Mohs' hardness rating of 7.0
The colored varieties of corundum, with the color coming from iron and titanium. Mohs' hardness rating of 9.
Colorless quartz
Mohs' hardness rating of 7.
Amethyst was a valuable gem until the discovery of large deposits in South America in the late 1800s; Brazil is the primary exporter to this day, although it is common in many countries. Still, its deep and attractive color makes it extremely popular. Banding - darker and lighter zones of color - is quite common. A good amethyst will be very clear, and the deeper the color, the better. The most common enhancements are heat and irradiation. Try not to expose an amethyst to excessive amounts of bright sunlight, as this can fade its color.
Pale lilac to deep purple
The most precious form of quartz, amethyst receives its color from iron and manganese. Durable, with a Mohs' hardness rating of 7.
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Pear-Shaped Pink Amethyst Ring in 10K Rose Gold with Diamond Accents 
Mohs' hardness rating of 7 to 7.5
Micro-crystalline quartz (chalcedony). Mohs' hardness rating of 6.5 - 7.0.
Nearly all tanzanite is heated at low temperatures to remove brown undertones and give a more desirable blue/purple color. A considerable portion of all sapphire and ruby is treated with a variety of heat treatments to improve both color and clarity.
When jewelry containing diamonds is heated (for repairs) the diamond should be protected with boracic acid; otherwise the diamond (which is pure carbon) could be burned on the surface or even burned completely up. When jewelry containing sapphires or rubies is heated (for repairs) it should not be coated with boracic acid or any other substance, as this can etch the surface; it does not have to be "protected" like a diamond.
RADIATOR
WAXING/OILING
Emeralds containing natural fissures are sometimes filled with wax or oil to disguise them. This wax or oil is also colored to make the emerald appear of better color as well as clarity. Turquoise is also commonly treated in a similar manner.
FRACTURE FILING
Fracture filling has been in use with different gemstones such as diamonds, emeralds and sapphires. More recently (in 2006) "Glass Filled Rubies" received a lot of publicity. Rubies over 10 Carat (2 g), particularly sold in the Asian market with large fractures were filled with lead glass, thus dramatically improving the appearance (of larger rubies in particular). Such treatments are fairly easy to detect.
GEMSTONE COLOR is the most obvious and attractive feature of gemstones. The color of any material is due to the nature of light itself. Daylight, often called white light, is actually a mixture of different colors of light. When light passes through a material, some of the light may be absorbed, while the rest passes through. The part that is not absorbed reaches the eye as white light minus the absorbed colors. A ruby appears red because it absorbs all the other colors of white light - blue, yellow, green, etc. - except red.
There is no universally accepted grading system for any gemstone other than white (colorless) diamond. 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).[2]
For the past several hundred years, gemstones have been broken down into two categories; precious and semi-precious. Though today we think primarily of diamond, ruby, sapphire, and emerald as "precious", these categories are based mainly on fashion and the composition of these two lists has changed frequently over time.[3]
Recently a mnemonic device, the "four C's" (color, cut, clarity and carat), was introduced to help the consumer understand the factors used to grade a diamond.[4] 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). This is a function of cut. 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, 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.[5]A factor in determining the value of a gemstone is called water. Water is an archaic term that refers to the combination of color and transparency in gemstones; used hierarchically: first water (gem of the finest water), second water, third water, byewater.[6]
Historically gemstones were classified into precious stones and semi-precious stones. Because such a definition can change over time and vary with culture, it has always been a difficult matter to determine what constitutes precious stones.[7]
Aside from the diamond, the ruby, sapphire, emerald, pearl (strictly speaking not a gemstone) and opal [7] 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 trade.
[6]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 bixbite.Gems 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 5USD/carat for a normal amethyst to 20,000-50,000USD for a collector's three carat pigeon-blood almost "perfect" ruby.