In my last blog I was talking about diamonds; those precious glitters with an fabulous price. And I told you why they were so expensive: due to their brilliance, their color and their clearness. And the fact that mining cooperation De Beers in South Africa only allows a small amount of diamonds on the market to stabilize the price (high!).

Well what happened since last november



In a diamond mine in Botswana (the country north of South Africa) they found a diamond of 1109 carat, which weighs 222.2 gram/7.8379 ounce / 0.4899 pound. That is as big as a tennisbal and the diamond is 3 milliard years old ( years). To find him they used a special machine, well suited to find diamonds. That enormous diamond is called Lesedi la Rona, which means ‘our light’ in the African language Tswana.

What does that mean: 1109 carat?

Carat is the unity for mass, used for gemstones. One carat is defined as 200 milligrams / 0.007 ounce. Normally we don’t wear a jewel with more than one carat, so the diamond industry uses also the point unit: that is equal to one-hunderth of a carat (0.01 carat = 2 milligram). When you have a ring with a lot of small diamonds in it, they don’t mention the weight of each diamond, but give you the total weight of all the little diamonds together.

Where does ‘carat’ come from?

Originally it is a Greec word (‘keratia’), which means the seed of a carob tree. In the past many countries used their own definition of a carat, but all where based on the weight of that carob tree seed. Those seeds were very usefull since they had a constant mass and could be used on the precision balances. In 1907 they decided that one carat was 200 milligram, that could be devided in 100 points, like 0.15 carat of 15 points.

What is the price of one carat of diamond?

First of all I have to mention that one carat in smaller diamonds has not the same price as a one carat diamond. A diamond of 0.98 carat is much cheaper than a diamond of 1.02 carat. Because of the differences in demand and the rareness of such gemstones. People, who can afford it, like a diamond of more than one carat.

Another thing to regard in this matter is that there are fake diamonds on the market of exactly one carat. They are more or less machine made. So with a diamond of a little more than one carat you know that the diamond may not be as clear as supposed to, but it’s not a fake. Big advise: buy your diamonds in a trustworthy jeweller store and ask for a certificate, that describes the diamond in full. There is a diamond price list, published every week by the Rapaport Group of New York. It mentions the prices of different cuts, weights and clarity.

The expected price of the Lesedi la Rona

Auction house Sotheby’s in London tries to sell the Lesedi la Rona on the 29th of june. They expect that the result will be 60-70 million Euro’s / 88 million dollars / 55 million pounds.

It’s big business for Sotheby’s, since never a diamond like this is auctioned before. And anybody can make a bid. The highest price for a diamond, sold on an auction was for the Blue Moon Diamond. This was a diamond of 12.03 carat, blue of color and a very rich man from Hongkong bought this beauty for the price of 42 million Euro’s. It was a present for his seven year old daughter!

The Blue Hope Diamond

The Blue Hope Diamond

After the buying…. The cutting

The Lesedi la Rona is an exeptional clear piece of rough gemstone. But the value goed up when the diamond can be set in a piece of jewelry. And here the cutting comes in. After the cutting you know how big or how much carat this diamond is; maybe the biggest cut diamond in the world.

The until now biggest diamond in the world is the Cullinan, of 3106 carat. The rough diamond was found in 1905 in South Africa. After cutting in Amsterdam / The Netherlands they ended up with 9 big and 96 small diamonds, which are used for the crownjewels of the Queen of Great Brittain.

The diamond cut

The diamond cut is a style or design guide. Cut does not refer to shape (pear, oval), but the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond’s brilliance.

In order to use a diamond gemstone’s material properties best, a number of different diamond cuts have been developed. A diamond cut constitutes a more or less symmetrical arrangement of facets, which together modify the shape and appearance of a diamond crystal. Diamond cutters must consider several factors, such as the shape and size of the crystal, when choosing a cut.

a solitair ring with a brilliant cut diamond

a solitair ring with a brilliant cut diamond

The most popular of diamond cuts is the modern round brilliant, which facet arrangements and proportions have been perfected by both mathematical and empiricalanalysis.

Although the weight of a diamond has the strongest effect on the price, the cut can still drastically increase or decrease its value. This is because there is a higher wastage of the rough stone as more material needs to be removed in order to achieve better proportions and symmetry. On top of that, there are additional costs for skilled labor since polishing an ideal cut diamond requires significantly more time.

Well I keep you informed about for what price this Lesedi la Rona Diamond will be sold tot he highest bidder.

When you like reading about the gemstones and everything around it, read my blogs. You can find them on my website. But when you subscribe to my newsletter, I will let you know when a new blog has been published. Use this link to subscribe (scroll down on this page)

Hug Florence


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