Working out rarity

[Alex Smith]

Are there any grafts or stats on diamond rarity. I juat wanted to see how rare my diamond was? Im trying to put my oval into context with other diamonds on the market. Its a 1.3ct oval, FL, D colour, ex.

I like placing things into stats.

 

[rockysalamander]

• Gem quality clarity (IF through I) make up about 15% of the worlds diamonds.
• Per Whiteflash..."D color (perfectly colorless) IF (internally flawless) diamonds are estimated to represent a miniscule .001% of world diamond production. Because diamond prices are based upon rarity, the price premium for perfect color and clarity is substantial."https://www.whiteflash.com/about-di...ure-perfection-d-flawless-a-cut-above-923.htm
• The larger the diamond with IF, the more rare. So, a 5 carat IF is dramatically more rare than a 1 carat.'

There is no single database every diamond every mined in logged into. So, I doubt there is anything 100% accurate. But, maybe a trade member can comment.

You should ask the mods to remove the duplicate thread.

 

[Diamond_Hawk]

Its a 1.3ct oval, FL, D colour, ex. .

Can you verify the lab who generated the grading report? GIA, HRD, IGI, etc...

 

[Karl_K]

The real answer is, no one really knows.
All the numbers floating around are pure guess work.

Even the 15% number is a guess.
Some mines they are lucky if a fraction of a percent is gem grade and other mines it may be as high or higher than 20%+.
It also varies with the age of the mine.
One mine in SA it is a very very small fraction of a percent but the ones that do come out are large and high grade. De Beers finally gave up on it but I believe another company is mining it still.

 

[Alex Smith]

Can you verify the lab who generated the grading report? GIA, HRD, IGI, etc...

Its GIA.

Thanks everyone. Didnt know if it was something like 1 in a 1000 or 1 in 10000. What would peoples educated guess be. Say if i was looking at the current market of new diamonds.

 

[whitewave]

There is no way to tell.

It would be a fake statistic to guess.

 

[diamondseeker2006]

To the wearer, those statistics don't matter very much. I'd honestly rather have a nice white F VS1 that was larger than a D IF!

 

[pyramid]

I don't know where you would find this type of thing out unless asking a diamond appraiser? I don't feel this forum is the right place as rarity and colorless diamonds are usually put down here in favour of cut. Maybe another diamond forum or a bricks and mortar jeweller such as Graff, Cartier would have more information. I know the jewellers in the UK are far more into high colour than this USA site here is.

 

[bmfang]

A FL diamond will remain that way provided that it isn’t set. Once set into a piece, it’s possible that it could get a downgrade to an IF clarity stone if there are any minor scratches on the surface.

An good appraiser would be the best person to gauge whether the stone is worth more or not. If it is a badly cut oval which exhibits a very prominent bow tie, it could be worth much less than another D FL oval which has been cut better.

 

[Texas Leaguer]

The real answer is, no one really knows.
All the numbers floating around are pure guess work.

Even the 15% number is a guess.
Some mines they are lucky if a fraction of a percent is gem grade and other mines it may be as high or higher than 20%+.
It also varies with the age of the mine.
One mine in SA it is a very very small fraction of a percent but the ones that do come out are large and high grade. De Beers finally gave up on it but I believe another company is mining it still.

I think you may be referring to the Letseng mine purchased by Gem Diamonds several years ago. Using some new technology they were almost immediately able to start harvesting some jumbos of top color and clarity. http://www.nationaljeweler.com/diam...em-diamonds-finds-6th-100-carat-stone-of-2017

 

[Karl_K]

I think you may be referring to the Letseng mine purchased by Gem Diamonds several years ago. Using some new technology they were almost immediately able to start harvesting some jumbos of top color and clarity. http://www.nationaljeweler.com/diam...em-diamonds-finds-6th-100-carat-stone-of-2017

I think that is the one.
Thank you!

 

[oldminer]

The pricing of certain categories of diamonds gives a clue to the rarity those certain categories. The fancy colored ones, the flawless ones, the largest ones, the natural colorless 2A types. Those are the ones which immediately come to mind. There may be others, too.

In the general market, the pricing is based on an arbitrary grading system of color, weight, clarity, and cut that everyone in the trade fairly much adheres to, but the actual supply nature provides of each identically graded type is somewhat of a mystery to most dealers and market participants. Maybe a few people do have access to the supply which nature provides to miner's by quality, but I'd say they are fairly tight-lipped about sharing it broadly. Who knows what kinds of rough are stockpiled due to lack of demand and which are pushed out rapidly due to strong demand and no stockpiling? We may know a lot about demand, but we know far less about the supply side.

 

[Texas Leaguer]

Its GIA.

Thanks everyone. Didnt know if it was something like 1 in a 1000 or 1 in 10000. What would peoples educated guess be. Say if i was looking at the current market of new diamonds.

Alex, you have a gem of exceptional rarity. Just how rare statistically is very hard to say and is dependent on other factors such as diamond type, fluorescence and cut quality.
Many, but not all, D FL diamonds are type IIa, characterised by an almost total absense of nitrogen impurities.
As others have pointed out, as size increases, rarity increases exponentially. Which is why cutters tend to try to squeeze every last point of carat weight out of the rough, often resulting in significant compromises in cut quality. (This is generally true of all high end rough, but particularly true of D FL). Since a diamond cut purely for beauty would tend to be smaller in weight, determining fine details of cut quality would be necessary to accurately assess rarity. Even then putting a number on it would be an exercise in "guestimation".

 

[Karl_K]

With modern cuttting I dont think even the miners would know for sure how many are cut into IF.
Modern planning tools make it much easier on a large scale to cut an IF stone by selecting clean portions of the rough to put inside a diamond.
I can see the decision coming up a lot x ct if vs y ct vs or even si.
Then they have to decide which will sell for a higher price.
If I recall right the automated planning tools have a setting where you can have them come up with the highest clarity plan and a largest yield plan at the same time.

 

[denverappraiser]

How about this?:

The database here has 495,000 round diamonds between 0.23 and 10 carats. 775 of those are described as D/IF. That’s about 0.15%.

Even this is a hugely skewed statistic because reportedly 90% of the diamonds mined are not gem quality in the first place. They’re used for things like industrial abrasives and such. That drops the percentage of total considerably. 0.015%

Then there’s the problem of self-selection. ALL 4 carat D/IF’s have lab papers, rather few 0.20ct /L/I-1’s do. It’s not a scam, it just doesn’t make economic sense to include an expensive lab service with the less expensive goods. Looking at an online sales database that lists only lab graded stones is, by it’s nature, skewed towards the better, or at least more expensive, stones. Few stones below 0.25cts will see a lab even if they’re super high grade and easily 90% of diamonds are sold without lab papers for this reason. Think about all those diamonds in tennis bracelets and around the bezels of watches.

Add all that up and a lab graded D/IF is something like 1 out of 10M diamonds. Possibly less.

 

[denverappraiser]

I noticed too late that we're talking about ovals. Using the same approach, there are 25818 ovals in the database at the moment. 7 of those are D/FL.

 

[Alex Smith]

Thanks all for your input. I underestimated the complexity of the question.