How Does The Lesotho Diamond Measure Up?

Early this year the world’s fifth largest gem-quality rough diamond was found at Lesotho
Africa’s Letseng mine. D in color and weighing in at 910 carats, the gem is the largest
diamond to have been found in that particular mine and is estimated to be worth
$40million.

The size is striking, comparable to a baseball in size and weight, but how does it measure
up to other large gem-quality diamonds found?

Starting with the most famous and by far the largest gem-quality rough diamond ever found,
the Cullinan.  It was discovered by Thomas Cullinan from the Premier No. 2 Mine in Cullinan,
South Africa in 1905. Weighing a whopping 3106.75 carats, the stone was ultimately cut into
9 stones total by the Asscher brothers.  The Cullinan I and II were used in the British Crown
Jewels while the other 7 stones remained with the Asscher family.  Even cut, the Cullinan is
still record holding.

The Cullinan I is the world’s largest clear cut diamond weighing in at 530.4 carats and D in
color. This Great Star of Africa, currently resides in the scepter of the British Crown Jewels
on display at the Tower of London.

The Cullinan II, the Lesser Star of Africa, is that second largest clear cut diamond weighing
in at 317.4 carats.  This stone is also part of the British Crown Jewels, set in the front of the
Imperial State Crown below the Black Prince’s Ruby (famously misnamed and is actually a red spinel).

The second largest gem-quality rough diamond is the Lesedi La Rona. It was found in the

Karowe Mine of Botswana in 2015 weighing in at 1109 carats.  The stone was purchased in
2017 by Graff Diamonds and has since been cut into smaller sellable stones.

Then we have the Excelsior Diamond which was the world’s largest gem-quality rough

diamond prior to the discovery of the Cullinan and is currently ranked third among its peers
in that category at 970 carats. The Excelsior Diamond was found in 1893 at the Jagersfontein
Mine in South Africa and has since tragically been cut into 21 insignificant stones that were
sold to several different buyers. One of the famous jewelry pieces to come from this stone is
a bracelet holding the 69.68 carat pear Excelsior I.  The stone was cut by the Asscher
Diamond Company in 1903 and eventually sold to and set by Robert Mouawadin 1996.

Finally we have the fourth largest gem-quality stone, the Star of Sierra Leone, extraordinarily

close in weight to the Excelsior Diamond at 968.9 carats. It is the largest alluvial diamond
ever discovered and was uncovered by miners in 1972 in the Diminco alluvial mines in Sierra
Leone. Harry Winston purchased the diamond and had it cut into 17 stones. Six of these
diamonds are present in Harry Winston’s “Star of Sierra Leone” brooch.

It seems that Africa is still the juggernaut when it comes to large gem-quality rough.
Impressively, only two of these diamonds are known to have been found using modern LDR
technology, the Lesedi La Rona and the Lesotho.

I can’t wait to see if how this magnificent stone ends up, whether it is cut into several smaller
pieces to be auctioned or if a mighty stone is cut and set into a work of art. Either way it is
definitely a stone to stay tuned into.