The Transvaal Blue Diamond

By 19.06 September 20th, 2018 No Comments

Blue Diamonds owe their intense blue colour to the presence of trace amounts of boron within the crystalline lattice structure, which, when illuminated with ultra-violet light, give off a unique blue glow which is not seen in any other fancy coloured diamonds.

The Transvaal Blue Diamond, a pear cut diamond weighing 25 carats, was found in the Premier Diamond Mine in South Africa. It was initially owned by Baumgold Bros, but its whereabouts today are unknown and remain a mystery.

Other Blue Diamonds

In honour of the founder of the Premier Mine, Sir Thomas Cullinan, in November 2003 the mine was renamed the Cullinan Diamond Mine. It is now known as the Petra Diamond Mine having been acquired in July 2008 by a consortium led by Petra Diamonds. One of the Blue Diamonds found in this mine is the Petra Blue Star of Josephine weighing 7.03 carats and sold in Geneva at the Sotheby’s auction in May 2009 for a record US$9.5 million.

Most of the famous Blue Diamonds were found in this mine. The Premier Blue Diamond is one of its most famous rare stones: it weighs 7.59 carats, is a fancy vivid blue in colour, is internally flawless and has a round, brilliant cut.

transvall blue diamond

Blue diamonds are found in only a few locations in India, South Africa and Australia.  The earliest recorded Blue Diamond is the Hope Diamond found in the Kollur Mine in Golconda, India in the 17th Century. Initially named the French Blue Diamond, it was stolen from the French Crown Jewels in 1762 during the French Revolution.

Other famous Blue Diamonds are:

The Blue Heart, sometimes known as the Unzue Diamond, weighing 30.82 carats and cut by Atanik Ekyanan of Neuilly, Paris, in 1909. It was owned for 43 years by an Argentinian woman, Mrs Unzue, who bought it from Cartier’s in 1910. In 1953 it was bought by Van Cleef & Arpels who reset it in a pendant surrounded by 25 white diamonds. It was sold to a European titled family for US$300 000.

The Blue Heart

The Heart of Eternity from the Premier Mine, a vivid blue diamond, weighing 27.64 carats, cut by the Steinmetz group and now owned by the De Beers Group.

The Heart of Eternity

The Wittelsbach-Graff Diamond, found in the Kollur Mine in India, passed through Austrian royalty, after which is was sold at an auction in 2008 to Laurence Graff.

The Wittelsbach-Graff Diamond

The Sultan of Morocco Diamond, also found in the Kollur Mine, was owned originally by the Yousupov family and Russia, and then passed on to the Sultans in Morocco.

The Sultan of Morocco Diamond-blue

The Zoe Diamond, probably found in South Africa, and weighing 9.75 carats, was sold in 2014 for the highest price ever for any diamond at that time. Originally owned by Rachel ‘Bunny’ Mellon, it was sold at an auction for $32.5 million to Hong Kong billionaire Joseph Lau, for and named after his daughter, Zoe.

The Zoe Diamond

The Oppenheimer Blue Diamond from the Premier Mine in South Africa, broke the Zoe Diamond price record when it was sold at an auction in 2016 for $58 million, making it the current record diamond sale price.

The Oppenheimer Blue Diamond

Blue Diamonds are excellent investment appreciating options, not only for their beauty, but for their unique value as they are sold at premium prices per carat size.

In 2014 two blue diamonds were found in the Petra Diamond Mine, one weighing 29.62 carats and then another at an incredible 122.52 carats. One can only imagine the investment value of these two blue diamonds.






The international unit of weight, used for measuring diamonds and gemstones. 1 carat is equal to 200 milligrams, or 0.2 grams.






Nothing is more impactful on a precious stone’s brilliance than its cut. The cut refers to the angles and proportions of a diamond. Known in the industry as ‘fire’, referring to the coloured light reflected, and ‘brilliance’ for the uncoloured light. The cut of a diamond – its form and finish, its depth and width, the uniformity of the facets – determines its beauty. The skill with which a diamond is cut determines how well it reflects and refracts light. A diamond should be cut proportionally, neither very shallow not very deep, given its dimensions. A diamond’s cut is its most important characteristics and a measure of its apparent beauty.


A diamond certificate or grading report provides an expert opinion on the quality of the diamond and is provided by an independent gemology lab. Trained gemologists with specialized equipment measure the weight and dimensions of the diamond and assess quality characteristics such as cut, color, and clarity. Brilliant Earth diamonds are certified by the world’s leading gem grading labs including GIA, IGI, and GCAL.


The height of a diamond, from the culet to the table referred as a Depth of the diamond . Depth % is the height of the diamond as a percentage of the girdle diameter.



Table referred as the largest facet of a gemstone, located at the top. Table % is the table width as a percentage of the girdle diameter.



Polish refers to the smoothness of the exterior of a diamond. Polish is graded from Ideal, Excellent, Very Good, Good, Fair, or Poor. Polish grades of Good or higher have the least effect on the brilliance of the diamond and recommended by us for the finest quality jewelry.


Symmetry refers to the angles to which the facets are aligned. Basically exactness of the shape of a diamond, and the symmetrical arrangement and even placement of the facets. If facets are misaligned, the diamond may poorly reflect light. Symmetry is graded from Excellent, Very Good, Good, Fair, or Poor. We recommends diamonds with Good or higher symmetry grades.


Describes the diamond’s response to ultraviolet light. In diamonds with strong or very strong fluorescence, there may be some interference with the flow of light which causes a milky or oily appearance. Canadian diamonds almost always have none to slight fluorescence.


Diamonds with “fancy” shapes are measured according to their length, width and depth. These diamonds will have a longer axis (the biggest measurement) and a shorter one that represents their width. The depth indicates the measurement of the diamond from the bottom to the top. The relative proportions of a diamond ultimately affect its quality and value.

Round-shaped diamonds are never perfectly round even though they may seem to be that way when you look at them. There is a tiny variation between maximum and minimum diameter, so dimensions are reflected as measurements of maximum diameter, minimum diameter and depth.

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