Golconda D

Thanks for your comments Mr. Richard Wise, on our webpage titled the Golconda-D diamond, and the question raised by you about its grading and fluorescence rating.
The Golconda-D diamond reported to have been purchased by Laurence Graff from its previous owners in Bombay, and slightly re-cut and polished to a 47.29-carat, internally flawless, round brilliant-cut, D-color diamond, is a product of the renowned House of Graff, and is listed among the 41 Important Gemstones, that had passed through their workshops, and had been either sold to their customers or still retained by the company. As a matter of policy all Graff diamonds sold by the company are accompanied by a GIA certificate, which verifies the cut,clarity, color and carat-weight of each diamond. Besides this, all Graff diamonds are also laser-inscribed on the girdle with the Graff Logo and the GIA identification number.
Hence we can assume, that the same standards would have been applied to the Golconda-D diamond as well, and the diamond would certainly have undergone testing by the GIA. Diamond Grading Reports issued by the GIA also includes a section on fluorescence rating, that gives the strength and color of the diamond when viewed under long-wave ultraviolet light. Unfortunately, we are not aware of the fluorescence rating of this diamond, and most websites only give prominence to the 4Cs of the diamond. However, if as it is claimed,the diamond is a Golconda diamond, in all probability the fluorescence rating should be "none" which represents a range of fluorescence from indiscernible to very faint.

What are the criteria applied to decide whether a given Type IIa, D-color diamond also known as "top color" diamond, qualify to be categorized as a "Golconda" diamond?

According to gemologist Richard W. Wise for a Type IIa, D-color diamond to be characterized as a Golconda diamond, it should possess at least three visual characteristics :-
1) A high degree of transparency, known as "limpidity" by Ian Balfour, "Super Crystal" by Richard Wise, and "Super-D" by some dealers.
2) An ultra-whiteness, variously referred to in superlatives as "whiter than white," "brighter than bright," "diamond of the purest water." "more colorless than colorless," "purest of the pure' etc.
3)The appearance of a blue afterglow in direct sunlight, despite the fact that most of these Golconda diamonds do not show any discernible fluorescence either in short or long-wave ultra-violet light. Such diamonds in the past were known as blue-white diamonds. However, the term blue-white today is used to describe diamonds that exhibit blue ultraviolet fluorescence. The "Regent diamond" is an example of a true legendary blue-white diamond.
The Golconda diamond mines were almost totally exhausted by the mid 18th-century, around 1750s. However, Type IIa diamonds originating from other sources, such as Brazil, South Africa etc. may also be characterized as "Golconda" if they possess the above three visual characteristics.
The following image is that of the legendary, true, blue-white, Golconda diamond, the Regent diamond :-
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The criteria laid down by the Gubelin Gem Lab based in Lucerne, Switzerland, to characterize a diamond as Golconda is more stringent than other authorities. These characteristics are :-
1) The diamond should be Type IIa.
2) The clarity of the diamond should be flawless, internally flawless or potentially internally flawless.
3) The diamond should have a D-color grade, absolutely colorless with a high degree transparency.
4) Genuine Golconda diamonds must have an antique flair, exhibiting features typical for antique cuts, before 1920, the year the modern brilliant-cut was introduced.
5) The diamonds should have antique shapes and cuts, prevalent before the introduction of the modern round brilliant-cut in 1920, such as cushion shape, old-pear shape, oval shape, marquise shapes with rounded ends, and baroque shape and cuts such as the old-European cut and the old-mine cut. Modern cut diamonds such as round brilliant stones cannot qualify for Golconda.
The following is a photograph of a baroque brilliant-cut/old-European cut Golconda diamond from the Gubelin Gemlab website :-
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The Gubelin Gem Lab criteria for Golconda diamonds do not mention anything about the blue afterglow in direct sunlight observed in many Golconda diamonds, even though such diamonds do not show any fluorescence.

Thanks Joan for making this important observation. However, the stringent Gubelin criteria for clarity, color, transparency, cut and shape, will automatically ensure that only genuine diamonds will qualify for Golconda classification, and this will undoubtedly include the blue-white Golconda diamonds. Nevertheless, the appearance of a blue afterglow in direct sunlight which is characteristic of most Golconda diamonds, can be used as a confirmatory feature, once a diamond has been identified positively as a Golconda under the Gubelin criteria.

I stumbled upon this pair of rare magnificent, old-mine cut, pear-shaped Golconda diamonds, with ear pendant mounts weighing 27.72 carats and 33.83 carats, that appeared at the Christie's Geneva Magnificent Jewels Sale 1327, held at Hotel Richemond on May 19, 2005. The pair of diamonds sold for US $4.07 million, above the upper pre-sale estimate of US $3.95 million.

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Thanks Peter, for your post. Your contribution is timely and relevant to our discussion.

Hi Peter, thanks for your update. I am sure there must have been a lab report accompanying these diamonds. Can you please give us more details.

In fact there had been two lab reports accompanying this lot - one from the GIA and the other from the Gübelin Gem Lab.
The GIA reports, nos. 14287350 and 14287352 dated February 23, 2005, pertaining to the two diamonds state, that the diamonds are old-mine cut, pear-shaped, D-color, VS1 clarity but potentially flawless.
the GGL reports, nos. 0503120 and 0503119 dated 16 March 2005, state that the diamonds are Type IIa, D-color, VS1 clarity but potentially flawless, possess an antique cutting style rarely encountered in the gem trade today.
The lot description further states- "The diamonds display a colour and degree of transparency which are particular to these unique gemstones. Diamonds of this type, exhibiting an antique cutting style as well as a fine quality, are very rare and will most certainly evoke references to the historic term of "Golconda"'.

I was able to locate the Christie's Lot Finder pertaining to the sale stumbled upon by Peter. The pair of magnificent Golconda diamonds referred to by Peter, was Lot No. 446 in this Christie's Magnificent Jewels Sale held in Geneva on May 19, 2005. A well written account on "Golconda Diamonds," their unique characteristics and what sets them apart from other diamonds that was published as a Pre-Lot Text is fully reproduced below for the benefit of our readers.

GOLCONDA DIAMONDS
Universally esteemed as the finest diamonds, 'Golconda' is a name used within the jewellery world to denote diamonds which possess superb luminousness and transparency. Besides indicating a superior quality, the term also indicates that the diamond is an old stone, mined in the ancient diamond fields of Eastern India.

The characteristic which sets Golconda diamonds apart from all other diamonds is a subtle luminous quality. It is an attribute which causes otherwise articulate connoisseurs to be at a loss for words when they attempt to describe it ..... "I could talk for hours about Golconda stones. But to really know what I am trying to tell you, you must hold one in your hand. Only then will you understand".

Golconda diamonds have a degree of transparency rarely seen in stones from other countries, such as South Africa, Russia, Canada or Australia. It is variously called, soft, limpid, watery or pure. It is not to be confused with clarity or freedom from flaws - it is rather a quality in which light appears to pass through the stone as if it were totally unimpeded, almost as if the light were passing through a vacuum. In addition, the surface lustre appears to have a light softness, more gentle and yet luminious and striking.

For the connoisseurs, the Golconda diamonds which retain their original cuts are most appreciated. Since the stones may have been mined hundreds of years ago, many exhibit the slightly less than precise cutting styles common prior to this century. This older cut tends to emphasize the limpid transparency which makes Golconda diamonds so special.

It is widely accepted that all diamonds which display this special luminousness are of Indian origin. Although little is recorded of the very early days of diamond mining in India, it is believed that it began about 400BC. For about 2000 years (with the exception of a small and protected source in Borneo), this was the only source of the precious gems until about 1725 when diamonds were discovered in Brazil, coincidentally at the same time as the majority of India diamond mines were depleted. Since 1829 the alluvial deposits have been worked in the Ural mountains of Russia and in 1866 the large diamond finds of South Africa were discovered. Diamonds in Australia were first recorded in 1851 but it was not until the 1979 that Argyle pipe was discovered and most recently Canada has become a forerunner in diamond mining. However, compared to the age of the Indian mines, all other diamond producing areas are comparatively recent discoveries.

The Indian diamond fields are found scattered throughout a broad belt of ancient rocks extending nearly one thousand miles in the north-south direction along the eastern half of the country. The vast majority of the diamonds found were from alluvial deposits - a secondary deposit formed by the breakdown of older rocks by the forces of nature and set down in river beds. Within the diamond belt diamonds were found in five distinct districts, each separated by high terrain. Each district had its own name, the most famous being the Golconda district centred around the area capital, trading centre and ancient fort of Golconda. Comprising Kistna and Godaviri valleys, mining activities reached its climax in the mid 1600s, according to the writings of the celebrated gem merchant and traveller Jean Baptiste Tavernier, and it is the Golconda district which is believed to have yielded the great historical diamonds of India, including the Koh-i-Noor, now part of the Crown Jewels of England, and the infamous deep blue Hope diamond, donated by Harry Winston to the Smithsonian Institute in Washington. Perhaps the historic Golconda diamonds most similar in shape and cut to lot 446 are the magnificent Indore Pears once owned by the Maharaja of Indore and sold by Christie's in November 1987 for $2.7m.

Today, diamond production is a fraction of what it was during the 1600s and is overshadowed by mining in Africa, Australia, Russia and Canada. However, it is still the Golconda diamonds which reign supreme among gem connnoisseurs around the world in terms of quality, mystery and romance.

The above account on the famous Golconda diamonds emphasizes the superior transparency and luminosity of these diamonds. The degree of transparency of these diamonds, not to be confused with clarity or being free from flaws, allows the free unimpeded passage of light, as if it were passing through a vacuum. The surface luster is soft and gentle, but luminous and striking. The writer compares the degree of transparency and luminous quality of Golconda diamonds, with diamonds from other countries such as South Africa, Russia, Canada and Australia and says such a degree is rarely seen in stones from these countries, a superior quality variously referred to as soft, limpid, watery or pure, which other writers had previously described in superlatives, such as "whiter than white," "brighter than bright," "more colorless than colorless," "purest of the pure" and "diamonds of the purest water."

Original Golconda diamonds are now extremely rare, and occur today only in museum collections or the collections of royalty and rich connoisseurs of diamonds. However, occasionally such diamonds come up for sale at auctions of renowned auction houses, such as Christie's, Sotheby's and Bonhams, and are snapped up by diamond connoisseurs, who are prepared to pay enhanced prices for such diamonds in keeping with their rarity. It was just last year on May 31st, 2011, at the Christie's Hong-Kong Magnificent Jewels Sale, a spectacular pair of diamond ear-pendants known as "The Imperial Cushions" incorporating two antique cushion-cut Golconda diamonds weighing 23.49 and 23.11 carats, appeared at the auctions and was sold for US $9.3 million, within the pre-sale estimate of US $7.1 million to $9.7 million.
The following is a photograph of this spectacular pair of diamond ear-pendants :-
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Thank you Anitap for your post. You have made another valuable contribution to our discussion.