Diamonds

4 C’s

Diamonds, by nature of their unique characteristics, can be evaluated much more precisely than other gems. Their extreme hardness allows ...
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3rd Century, Roman "Pointed" Diamond Ring. © The Trustees of the British Museum.

A History Of Diamond Cutting

This article gives an overview of the history of diamond cutting. For detailed descriptions of the different diamond cuts see ...
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6.79 Carat French-Cut Diamond, Angeled View.

Adamantine Luster

Adamantine is the term used to describe the luster exhibited by diamonds and gems with a Refractive Index of 1.9 - 2.5. The root word adamant ...
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A contemporary shot of the Agra.

Agra Diamond

Like many historical diamonds, the Agra’s saga is a familiar combination of fact and legend, leaving the reader with the challenging ...
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Shah Jahan ca. 1620

Akbar Shah Diamond

Unfortunately, the history of famous diamonds is not without its list of casualties. In this category are those magnificent stones that somehow ...
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Allochromatic

 The term allochromatic is used in reference to gem materials that derive their color from elements that are not an ...
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Anniversary Gifts

This anniversary gift list is a recent compilation that is recognized by the American Gem Trade Association, Jewelers of America, ...
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The Archduke Joseph Diamond

Archduke Joseph Diamond

This stone enjoys the distinction of being the twelfth largest “perfect” diamond in the world. Named for a military man of royal ...
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Arcot Diamonds Set in a Brooch.

Arcots

ARCOTS – A Pair of Diamonds They began their existence as nature had made them; two beautiful pear-shaped diamonds. Their ...
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Asscher Cut

In 1902 the Dutch diamond cutter Joseph Asscher developed the cut that would carry his name on into the future ...
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Baguette Cut

The baguette cut represents an elongated, rectangular table cut. The modern version, as in the ring on the right, was (re)introduced ...
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Banjarmasin Diamond

One could rightfully call this stone the Rodney Dangerfield of diamonds. Almost from the moment of its discovery, this diamond ...
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The Beau Sancy.

Beau Sancy

This diamond's name is taken from its first recorded French owner, Nicolas Harlay de Sancy, a fancier of fine gems who ...
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Brilliant Cut

Brilliant Cut Diamonds as We Know Them When we think of a diamond, most of us will form an image ...
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Briolette Cut

Briolette Cut Edwardian Garland Motif Pendant Suspending a Briolette Cut Diamond. Briolettes are drop shaped, multi faceted stones. They are ...
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2008 sketch of the Golden Fleece (of the Color Adornment) Showing the "French Blue" Diamond.

Brunswick Blue

To paraphrase Charles Dickens, this is a tale of two diamonds. Purportedly cut from the same stone that produced the Hope Diamond, ...
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Bruting

Bruting is a process in diamond cutting that establishes the girdle outline. Once the height and width of the diamond are determined, it is ...
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Carbon

Carbon is a chemical element on the periodic table. Carbon is the 15th most abundant element in the earth's crust ...
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Cleavage

DefinitionThe ability of a material to split along a certain plane or planes with weak atomic bonding. A crystal structure ...
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Minnie Palmer

Cleveland Diamond

If ever fate has lent a hand in determining the course of a diamond's story, it is this one. Just a ...
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The Nine Most Important Cullinan Diamonds. Top Row: II, I and III. Bottom Row: VI, VIII, IV, V, VII and IX.

Cullinan Diamond

It was the late afternoon of January 25, 1905. Employees at the Premier Diamond Mine in the British African colony ...
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Cushion Cut

Cushion cut is a sexy and romantic name for a squarish ("cushionesque") antique brilliant-cut diamond, sometimes referred to as an ...
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Darya-e-Noor Diamond.

Darya-ye-Noor Diamond

Darya-ye-Noor Diamond. Darya-ye-Noor, translating “river of light” or “sea of light”, is the product of an undocumented – but what ...
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Asscher-Cut Diamond Ring.

Diamond

Diamonds are valued for their incredible brilliance and hardness. Diamonds are chemically pure carbon, identical to the graphite used for ...
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Diamond Cutting & Grading

Diamond Cuts Main Article Gems & Gemology: The Quarterly Journal of the Gemological Institute of America Diamond Cutting & Grading: Summer ...
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The Dresden Green Diamond in its Setting.

Dresden Green

The Dresden Green Diamond in its Setting. Labeled as the greatest example of a naturally green colored diamond, the Dresden Green ...
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Emerald Cut

The Emerald Cut is a rectangular step cut design which means it has horizontal facets which differ in angles of ...
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The Emperor Maximillian Diamond Weighing 39.55 Carats. Photo Courtesy of Christie's.

Emperor Maximilian & Maximilian Diamonds

Although these two diamonds are often spoken about in the same breath, no two stones could be more different – ...
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Empress Eugenie (1853-1871)

Eugénie Diamond

Believed to be of Brazilian origin, this much-traveled diamond has not only changed hands many times, it’s also one of the few ...
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European Cut

Diamonds cut in the later 19th and early 20th-century cutting houses are called 'Old European Cuts', a term which indicates ...
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69.68 ct. Excelsior I, G-VS2. Photo Courtesy of Mauawad.com.

Excelsior Diamond

June 30, 1893, appeared to be just another day at the Jagersfontein Mine in South Africa until a worker, performing ...
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Facet

Definition A facet is a flat, planar surface ground onto a gemstone or diamond. Facets can be produced in many shapes and sizes ...
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Filling

Filling is a gemstone enhancement method which indicates a broad range of treatments. From simple oiling to resin impregnation to the filling ...
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Fire

A popular term used to describe the flashes of spectral colors displayed by a gemstone as the result of dispersion ...
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A Replica of the Florentine Diamond.

Florentine Diamond

Studying the history of this diamond is an exercise that will challenge even the most talented detective. Almost everything about this diamond’s ...
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French Cut

Art Deco French-Cut Diamond Straightline Bracelet. The term "French Cut" does not refer to the country of origin, rather It ...
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G&G Articles on Famous Diamonds

More Information Gems & Gemology: The Quarterly Journal of the Gemological Institute of America. G&G Article Index:  Famous Diamonds Below please ...
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Gadolinium Gallium Garnet aka GGG

GGG

Gadolinium Gallium Garnet. A synthetic gemstone used as an early diamond substitute. GGG is manufactured by the Czochralski method and ...
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Gill’s Index of G&G Articles 1934-1980

AmberSpring 1943, Amber, by Briggs, p. 78, 3pp.Fall 1959 A Pink Amber-Like Resin from Southern Calif., p. 337, 2pp.Fall 1963, A Painted Amber, ...
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Girdle

The band on a faceted stone, around the widest circumference, which creates the separation of the crown and pavilion of ...
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Golden Jubilee Diamond.

Golden Jubilee

If you record size as the number one trait in judging the importance of a diamond then this stone would top your ...
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Early Drawing of the Great Mogul Diamond.

Great Mogul Diamond

This is the kind of story that would make a great Indiana Jones movie – solving the mystery of the ...
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Warren Hastings

Hastings Diamond

If ever there was a famous diamond named for a certified scoundrel, it’s the Hastings Diamond. Using this gem as a tool ...
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Heart Shape

Main Article ...
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Holland Diamond (Stuart)

This is the story of a diamond whose beginnings and early history are unknown, a casualty of lost or poor documentation. It ...
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The Hope diamond. Image Courtesy of The Smithsonian Institute.

Hope Diamond

Thievery, royalty, revolution, gambling, eccentricity, mystery and curses are all part of the spectacular and storied past that is the ...
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Hortensia Diamond, 20.53 Carats, Pink.

Hortensia Diamond

It seems each famous diamond has some kind of mystery attached to it, usually involving the location of its discovery, the identity ...
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HPHT

HPHT treatment stands for high pressure - high-temperature treatment. This method of diamond enhancement, invented in the late 1960's, started to be applied commercially ...
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Idols-Eye Diamond.

Idol’s Eye Diamond

Like many of its contemporaries, the Idol’s Eye diamond possesses an early history that combines a rich mixture of legend, myth, mystery, ...
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Inclusion

Inclusions are internal features within a gemstone, often small enough to require a microscope for viewing. This term usually refers ...
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Irradiation

In 1904 William Crookes, a well known physicist discovers that diamonds turn green upon exposure to radium. The diamonds stayed radioactive and ...
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Kazanjian Red Diamond. ©Tino Hammid, Los Angeles

Kazanjian Red

Kazanjian Red Diamond.©Tino Hammid, Los Angeles This stone belongs to an extremely small – and select - group of diamonds ...
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The Koh-i-noor Set in the Coronation Crown for Queen Mary (Wife of King George VI) Mother of Queen Elizabeth II. (Reuters Photo)

Koh-i-Noor Diamond

The Fabled Koh-i-Noor Diamond Like other famous gems, the Koh-i-Noor diamond has its share of mystery, intrigue, and curses attached to its ...
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Laboratory Grown

Gemstones that are produced by man are generally termed "laboratory grown". These can be synthetics or other inorganic minerals that have no ...
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Laser Drilling

Surface reaching fractures containing dirt have long been boiled in acid or bleached to remove unwanted inclusions. About 10 years ...
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Louis II de Bourbon aka le Grand Condé

Le Grand Condé

Louis II de Bourbon - aka le Grand Condé If there was an award for the most gaps in a ...
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Lozenge Shape

A lozenge-shaped diamond is one that is rhomboid in outline. This geometric outline is also known as "diamond" shaped, but ...
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Macle

Macle is a gemological term referring to triangular shaped twinned crystals of diamond rough. Macles are usually quite flat but are often ...
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Marquise Cut

The Marquise Cut (a.k.a. the Navette Cut after the Latin 'navalis', meaning boat-shaped) can be traced back to Paris around ...
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Mazarins

This diamond story is an unusual one. In most instances, a name is attached to one or perhaps two diamonds but in ...
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Melée

The term melée is used to indicate very small cut stones, usually used as side stones around a bigger center ...
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Mirror of Portugal

Owners of this stone ranged from the tenacious to the hapless, the romantic to the cunning. This diamond helped persuade a Queen ...
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Moh's Scale of Hardness. Photo Courtesy of the National Park Service.

Moh’s Scale

Moh's scale is a relative hardness scale for minerals rating them from 1 to 10. The values are not proportional ...
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Mounting on Moor

"Mounting on moor" refers to the tinting of diamonds on the pavilion to create a more uniform color and to hide dark ...
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Mughal Cut

Around the Same Time, Diamond Cutting Began in Europe the Indians Started Fashioning Diamonds. Who Influenced Who Here Isn't Clear ...
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Naif

A Naif is the outer surface of an unpolished and uncut diamond. When cutting a diamond a small bit of this ...
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A Side View 13a, Top View 13b, and Bottom View 13c of the Nassak Diamond as of 1904

Nassak

This particular stone could be the reason for the cliché “diamond in the rough.” During its early history, this stone ...
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Natural

A natural is a bit of the naif or outer skin of a diamond that remains after cutting and polishing. A natural on ...
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Navette

Navette is another term to describe a marquise shaped gemstone or jewelry contour. Pointed at both ends with equally curved sides, the ...
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The Orlov diamond in the Russian Imperial Sceptre Image courtesy of Elkan Weinberg.

Orlov Diamond

Perhaps there is no famous diamond with a more disputed history than that of the Orlov. Through the passage of ...
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Oval Shape

Main Article ...
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Paste

Paste is a synonym for glass when used in the context of a gem material. Glass has been used as a gemstone imitation since ancient ...
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Paste Jewelry

Paste jewelry is costume jewelry, mainly set with colored and/or colorless glass. During the eighteenth century with the vogue for faceted gems and diamonds, the demand ...
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Pavilion

The pavilion is the part of a gemstone below the girdle ...
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Pear Shape

Pear-shape refers to the shape of a faceted gemstone that comes to a point at one end and is rounded at the opposite ...
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Louis-Jean Marie de Bourbon, (16 November, 1725 – 4 March, 1793)

Penthièvre

It is a diamond not as well known as its contemporaries. It is somewhat of an anomaly, for through its rich French ...
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George Pigot (4 March 1719 – 11 May 1777)

Pigot Diamond

With apologies to Charles Dickens, this diamond’s story could be entitled the “Tale of Two Diamonds” for its history diverges ...
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Pique

Pique is a technique in which gold or silver is inlaid in tortoiseshell and sometimes ivory or mother-of-pearl. Another meaning is the French word for an inclusion in a diamond ...
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Point Cut

Natural Points A Natural Octahedronby Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 Diamonds crystallize in various forms of which the octahedral and ...
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Princess Cut

Being one of the more modern diamond cuts the Princess Cut is often indicated as being a square brilliant but this is ...
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Queen of Holland

As diamonds go this one is pretty impressive, not only because of its size but because of its renowned quality ...
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Radiant Cut

Main Article ...
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Refraction

The change in the direction and speed of light as it passes from one medium into another of different optical ...
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Refractive Index

The ratio of the speed of light in air to its speed its speed in a substance. The ratio indicates ...
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Refractometer

A gemological instrument which works on the principal of total internal reflection and which is used to measure the refractive index of gemstones ...
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Regent Diamond

This magnificent gem has generated enough fodder to churn out a series of pulp fiction novels. Its travel through history is intertwined ...
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French Antique Silver, Enamel and Paste Necklace

Rhinestone

Rhinestone is the name given to rock crystal which is faceted to imitate diamond. It is also a name for ...
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Rose Cut

Rose-Cut Diamonds: Their Beauty and Allure Early "diamond cuts" were essentially diamonds altered with only minor changes and a light polishing before ...
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Rosettes

Rosettes are floral depictions built up out of several diamonds. They were used to make the most out of small ...
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Sancy Diamond

Diamonds tend to be described in such glowing terms as “beautiful,” “exquisite,” or “impressive.” The Sancy is that rare gem that ...
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Scintillation

Scintillation is the term that describes the flashes of light reflected off the facets of a gemstone as it moves ...
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Shah Diamond

Imagine a diamond where the reader is not faced with the challenge of trying to separate fact from fiction when researching its ...
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Shah Jehan Table-Cut

By any gemological standard, the Shah Jahan Table-Cut Diamond is one impressive stone. Like many of its contemporaries, this diamond has gone ...
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Shield Cut

The Term Shield Cut, as suggested by Tillander, indicates all historical triangular cuts. The basic blueprint comes from half an ...
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Single Cut

Old Single Cut The Old Single Cut is a variation to the early Table Cuts and is encountered from the earliest days ...
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Specific Gravity

The ratio of the weight of a substance to the weight of an equal volume of water ...
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Spectrum

Introduction The electromagnetic spectrum is best explained with the use of an image. On the right, you see an overview ...
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Stability

Gemstone stability refers to the stone's general resistance to fading, heat tolerance and ability to withstand chemical attack ...
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Strass

Glass with high lead content. The lead increases the refractive index, specific gravity and dispersion but lowers the hardness. Strass was invented in the 18th century by ...
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Swiss Cut

Swiss cut diamonds are the late 19th-century predecessor to the 20th century Single Cut. Their crowns are built up out of a table facet, ...
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Synthetic Diamonds In the Lab.

Synthetic Diamond

Video Presentation on Diamond Synthesis Gems & Gemology: The Quarterly Journal of the Gemological Institute of America.Synthetic Diamond:March-April 1935, Synthetic Diamonds, ...
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Art Deco Synthetic Cabochon Sapphire Ring

Synthetic Gemstone

Synthetic gemstones are artificially created gemstones that have the same chemical build up as their natural counterparts. They therefore harbour the same ...
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Table Cut

The term 'table cut' is used to indicate all types of cuts that have a table facet. Cuts that fall ...
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Table Facet

The table is the largest facet on the crown of a gemstone. This horizontal facet is measured from corner to corner ...
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68.09 ct. Taylor-Burton Diamond, Suspended from an Oscar Heyman & Bros. Necklace. Currently Owned by Mouawad.

Taylor-Burton Diamond

68.09 ct. Taylor-Burton Diamond, Suspended from an Oscar Heyman & Bros. Necklace. Currently Owned by Mouawad. This diamond is a stone whose ...
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Translucent

To be translucent is to transmit light, but diffusely, so that objects beneath cannot be clearly resolved. Translucent enamel is used to ...
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Transparent

Material through which an object can be viewed clearly, even through a considerable thickness ...
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Twinning

Growth process in which a twin crystal is produced. Often seen as fine parallel lines ...
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Wittelsbach-Graff Diamond.

Wittelsbach

The Wittelsbach-Graff Diamond.Image Courtesy of Christie's Images, 2008 It’s that rare diamond that could match its color to the blue-blood of its ...
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