Graff Lesedi La Rona: The British jewellery unveils the world’s largest square emerald cut diamond at 302.37 carats

Most expensive emerald cut diamond - Graff Lesedi La Rona

The renowned British jeweller also claims that the gem is “the largest highest colour, highest clarity diamond ever graded by the Gemological Institute of America (GIA)”

Diamonds are a girl’s best friend… but just how much do you really know about diamonds? For the uninitiated, the process of looking for the perfect stone can be very much simplified if you refer closely to the four C’s of diamond buying: Carat weight, colour, clarity and cut. But of course, the four Cs simply serve as a general rule of thumb to help us avoid making poor decisions when purchasing these gemstones.

There is so much more to appreciate in the realm of diamonds; from the untold journeys of miners who traverse some of the world’s most extreme boundaries to unearth exquisite beauties to the highly dedicated craftsmen who clock in weeks or months just to chisel a minimally cut diamond from its rough.

One renowned luxury jeweller who’s no stranger to the challenges of diamond acquisition is Graff, which has recently unveiled the Graff Lesedi La Rona, the world’s largest square emerald cut diamond weighing 302.37 carats. The glitzy, emerald cut gemstone is the principal diamond chiseled and polished from the 1,109-carat Lesedi La Rona rough. Acquiring the rough, of course, was no easy feat to begin with. Graff could only get their hands on the one-of-a-kind beauty after more than a year of negotiations with Canadian mining company Lucara Diamond Corp, which discovered the rough in 2015. The deal finally closed for a whopping US$53 million (S$71.7 million) in late 2017. This acquisition further cements Graff’s status as the ‘King of Diamonds’, as the prestigious jeweller’s portfolio now spans a majority of the world’s 20 largest diamonds found over the last century.

But just how rare is the Lesedi La Rona, and why exactly is it taking the diamond market by storm? Discovered at the Lucara Karowe mine in north-central Botswana, the Lesedi La Rona is about the size of a tennis ball, and is the largest quality rough diamond discovered in more than 100 years. It is also the second largest in history – the only other stone that exceeds its size is the iconic 3,016.75-carat Cullinan Diamond, mined in South Africa in 1905, which produced nine main diamonds that currently form part of the British Crown Jewels.

And even though Graff had the world’s second largest diamond rough in its lab, the jewellery dealer was far from the finishing line. Producing the world’s largest square emerald cut diamond from its rough took Graff 18 whole months. Yes, we’re talking about the mother of all diamonds here – one that will set you back much, much more than our fully-furnished, triplex Concourse Skyline Penthouse. Graff may had had experience in polishing a similar 373-carat rough diamond in 2016, which was believed to have derived from the same rough stone, but executing Lesedi La Rona posed a whole new challenge for its team of gemmologists. The gemstone was too large for their existing equipment and tool, so a scanner with a new sophisticated imaging software had to be custom-built to craft and polish the principal diamond.

The final outcome, of course, is an absolute marvel to behold. GIA has awarded the Graff Lesedi La Rona the D colour grade – the highest end of the GIA colour scale – which indicates that the stone exhibits very few or no blemishes. It is uncommon for any diamond to achieve this, much less one of more than 300 carats. Call it the diamond project of the century, because it truly is.  

The final value of the gemstone is still unknown, but we’re keeping our eyes peeled for the day it goes under the hammer. But knowing that it’s the “largest highest colour, highest clarity diamond” the GIA has ever come across, another record-breaking price tag in the realm of white diamonds is definitely in place.