4 C’s

Diamonds, by nature of their unique characteristics, can be evaluated much more precisely than other gems. Their extreme hardness allows ...
Read More
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 ...
Read More
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 ...
Read More
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 ...
Read More
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 ...
Read More


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

Anniversary Gifts

This anniversary gift list is a recent compilation that is recognized by the American Gem Trade Association, Jewelers of America, ...
Read More
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 ...
Read More
Arcot Diamonds Set in a Brooch.


ARCOTS – A Pair of Diamonds These two exceptionally beautiful pear-shaped diamonds began their travels from the Nawab of Arcot ...
Read More

Asscher Cut

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

Baguette Cut

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

Banjarmasin Diamond

One could rightfully call this stone the Rodney Dangerfield of diamonds. Almost from the moment of its discovery, this diamond has ...
Read More
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 ...
Read More

Brilliant Cut

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

Briolette Cut

Edwardian Garland Motif Pendant Suspending a Briolette Cut Diamond. Briolettes are drop shaped, multi faceted stones. They are unique in ...
Read More
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, ...
Read More


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


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


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

Cushion Cut

Cushion cut is a sexy and romantic name for a squarish ("cushionesque") antique brilliant-cut diamond, sometimes referred to as an ...
Read More
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 ...
Read More
Asscher-Cut Diamond Ring.


Diamonds are valued for their incredible brilliance and hardness. Diamonds are chemically pure carbon, identical to the graphite used for ...
Read More

Diamond Cutting & Grading

Diamond Cuts Main Article Gems & Gemology: The Quarterly Journal of the Gemological Institute of America Diamond Cutting & Grading: Summer ...
Read More
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 ...
Read More

Emerald Cut

The Emerald Cut is a rectangular step cut design which means it has horizontal facets which differ in angles of ...
Read More
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 – ...
Read More
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 ...
Read More

European Cut

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

Excelsior Diamond

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


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


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


A popular term used to describe the flashes of spectral colors displayed by a gemstone as the result of dispersion ...
Read More
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 ...
Read More

French Cut

Art Deco French-Cut Diamond Straightline Bracelet. The term "French Cut" does not refer to the country of origin, rather It ...
Read More

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 ...
Read More
Gadolinium Gallium Garnet aka GGG


Gadolinium Gallium Garnet. A synthetic gemstone used as an early diamond substitute. GGG is manufactured by the Czochralski method and ...
Read More

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, ...
Read More


Crown, Girdle, Pavilion The band on a faceted stone, around the widest circumference, which creates the separation of the crown ...
Read More
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 ...
Read More
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 ...
Read More
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 ...
Read More

Heart Shape

Heart-Shaped Diamonds. Main Article ...
Read More

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 ...
Read More
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 ...
Read More
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 ...
Read More


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 ...
Read More
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, ...
Read More


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


In 1904 William Crookes, a well known physicist discovers that diamonds turn green upon exposure to radium. The diamonds stayed radioactive and ...
Read More
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 ...
Read More
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 ...
Read More

Laboratory Grown

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

Laser Drilling

Laser Drilled Diamond. The Drill Channels you See are Not All Individual Channels, for the Most Part, They are Reflections.Image ...
Read More
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 ...
Read More

Lozenge Shape

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


Diamond Macle. Macle is a gemological term referring to triangular shaped twinned crystals of diamond rough. Macles are usually quite flat but ...
Read More

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 ...
Read More


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


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

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 ...
Read More
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 ...
Read More

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 ...
Read More

Mughal Cut

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


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


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


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


Navette is another term to describe a marquise shaped gemstone or jewelry contour. Pointed at both ends with equally curved sides, the ...
Read More
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 ...
Read More

Oval Shape

Oval Diamond Three Stone Ring. Main Article ...
Read More


Example of a Paste Sapphire Imitation. Notice the Rounded Facet Edges Which Tell Us the Stone Wasn't Cut, but Cast ...
Read More

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 ...
Read More


Crown, Girdle, Pavilion. The pavilion is the part of a gemstone below the girdle ...
Read More

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 ...
Read More
Louis-Jean Marie de Bourbon, (16 November, 1725 – 4 March, 1793)


It is a diamond not as well known as its contemporaries. It is somewhat of an anomaly, for through its rich French ...
Read More
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 ...
Read More


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. Victorian Pique Brooch ...
Read More

Point Cut

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

Princess Cut

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

Queen of Holland

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

Radiant Cut

Radiant-Cut Diamond. Main Article ...
Read More


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

Refractive Index

Portable Refractometer.The ratio of the speed of light in air to its speed its speed in a substance. The ratio ...
Read More


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

Regent Diamond

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


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

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 ...
Read More


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

Sancy Diamond

Sancy Diamond - Part of the Crown Jewels of France on Display at the Louvre. Diamonds tend to be described in ...
Read More


Scintillation is the term that describes the flashes of light reflected off the facets of a gemstone as it moves. Victorian Cluster Ring with ...
Read More

Shah Diamond

Imagine a diamond where the reader is not faced with the challenge of trying to separate fact from fiction when researching ...
Read More

Shah Jahan 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 ...
Read More

Shield Cut

The term shield cut, as suggested by Tillander, indicates all historical triangular cuts. The basic blueprint comes from half an ...
Read More

Single Cut

Old Single Cut An Old Single Cut; a Square Table Cut with Faceted Corners. The Old Single Cut is a ...
Read More

Specific Gravity

Specific Gravity is the ratio of the weight of a substance to the weight of an equal volume of water ...
Read More


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


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


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 ...
Read More

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, ...
Read More
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, ...
Read More
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 ...
Read More

Table Cut

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

Table Facet

The Crown is Comprised of the Table, Main, Star and Girdle Facets. The table is the largest facet on the crown of a gemstone. This ...
Read More
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 ...
Read More


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


Material through which an object can be viewed clearly, even through a considerable thickness. Transparent Rock Crystal Quartz Bead Necklace ...
Read More


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


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 ...
Read More
Yttrium Aluminum Garnet - YAG


Yttrium Aluminum Garnet - YAG ...
Read More