"These Rare Stones Are About To Become Priceless"

We've looked at the 'fancy's' as they are known a few times, links after the jump.
This post is not an offer to sell nor a solicitation of an offer to buy any pretty pink hunks of carbon.
Please contact your beloved, your investment counsel or your personal deity for further insight.

From SafeHaven, August 14:

Mining giant Rio Tinto is shutting down operations at its giant Argyle mine in Western Australia, and the anticipation is that move will great a supply shortage of pink diamonds.

The Argyle mine has reached the end of its production life, and now Rio’s precious gems rivals are expecting a lucrative surge in prices.
After all, Argyle produced some 90 percent of the world’s supply of pink diamonds.

Through the life of the mine, which launched in 1983, Argyle has produced some 800 million carats of rough diamonds, or around 8 million carats annually, and has been famously known for its pink and red diamonds, as well as brown and purpose.

Now, everyone is bracing for a major supply crunch.

For Q2 2019, Rio had recorded an output decline of 5 percent, compared to the previous quarter, and a 9-percent decline for H1 2019. For this year, Rio anticipates production of 15 to 17 million carats, but after that, it’s closing up shop by late-2020.

And it’s not only Argyle that’s reached the end of its production life ...

So what can we expect on the price front?
That depends in part on how many pink diamonds Rio’s got sequestered away in its stockpiles, and so far it’s remain tight-lipped on that.....MORE

Previously:
Sept. 2013
You Thought the Rio Tinto Red Diamonds Were Baubles, You Dismissed the 118 Carat 'Perfect' Being Auctioned Tomorrow as Crass, Perhaps Monsieur et Madame Would be Interested In...

...The Pink Star

November 2013
'Pink Star' Diamond Sells for World Record $83 million at Sotheby's Geneva
Here's the catalogue entry for lot 372 at the 2013 Geneva auction.

Possibly also of interest:
May 2013
Rio Tinto's Extremely Rare Red Diamonds (RIO)

June 2014
122.52 Carat Blue Diamond Found In South Africa (PDL.L)

^{The 122.5 carat diamond discovered by Petra}

Nice Rock: Christie’s Unveils the Aurora Green Diamond

For the most part diamonds are not investments, at best they are speculations except possibly in the case of the colored Fancy's.

From Diamond Investments:

I don’t recall the last time I was wowed by a diamond. When I see so many diamonds, research special diamonds, and discuss large numbers, that amount of zeros has no longer a meaning. It would take something really special to get me excited. Christie’s has just done it! And I think this will be the last one for this year…

Christie’s Aurora Green diamond, to be auctioned in Hong Kong     Image credit: Christies’s

In the upcoming Geneva auctions, Sotheby’s and Christie’s together have over 10 diamonds in pink and blue diamonds to be offered to the bidding crowd on the floor, on the phones, and to those that are bidding online. In fact, to be honest, I am a bit skeptical about the quantity of the special diamonds that will be offered in Geneva. I am concerned that there are not enough bidders for all these special diamonds. My concern is not because they are not worth the current estimates (some are worth even more than the high estimates). It is because even these wealthy people still require liquidity at these levels (unless they reach a side agreement with the auction houses), and they need to have the desire to own so many diamonds at any given one time.

I am concerned that the lack of buyers or bidders will end up causing some of the rare and beautiful diamonds not to sell. In the process, it may give the illusion that the unique diamonds are not worth the acquisition, and in turn will hamper the overall demand of fancy color diamonds, a misleading and unfortunate result.

I can honestly say that both Sotheby’s and Christie’s may be blamed if something like this happens. They are both under tremendous pressure from their investors to perform, as 2015 was a bad year for both in terms of jewelry sales in comparison to 2014. However, selling so many rare diamonds at once can prove to be equally harmful. It remains to be seen in less than 2 weeks what will result at the auctions.

Christie’s Unveils World’s Largest Recorded Fancy Vivid Green Ever to be Graded by the GIA
It is not a mistake nor is it a coincidence that the Fancy Vivid Green diamond to be sold at Christie’s Hong Kong was named the “Aurora Green” diamond. A phenomenon like the Aurora Borealis happens once in history, or at least it has been so up until now. The diamond which bears the name of this natural phenomenon is special for several reasons; the color, size, and clarity as well as a surprising characteristic which is unheard of for this color – its lack of Fluorescence.

Aurora Green Diamond
It has only happened once before in the history of either auction house that a Fancy Vivid Green diamond was available for auction. This shows us true rarity, as even the extremely rare diamond colors like pink and blue come up far more often than this. The only other time a Fancy Vivid Green diamond was auctioned was on November 17, 2009 when Sotheby’s auctioned the famous 2.52 carat Fancy Vivid Green diamond at their Geneva Magnificent Jewels auction. It sold for a “world record” of $3,078,914 or $1.222 million per carat.

The 2.52 carat Fancy Vivid Green diamond     Image credit: Sotheby’s

During that time, the world was in midst of the global financial crisis, so reaching such a price is more than significant. It also makes us think what the price could have been if the world was going through prosperity rather than a drought. That is a number we will never know.

Six and a half years later, the largest ever documented Fancy Vivid Green diamond is being offered at auction by Sotheby’s’ rival Christie’s. It is twice the size of Sotheby’s’ green diamond and stands at 5.03 carats (ok, almost twice the size). It is a rectangular shaped radiant cut diamond, a real deep and beautiful Vivid Green

The 5.03 carat Fancy Vivid Green ‘Aurora Green’ diamond set in a pink diamond halo setting     Image credit: Christie’s

We know that green diamonds get their color while forming from natural radiation inside the earth. There should be no worries, as this radiation is not harmful. What is extraordinary is that the Aurora Green diamond does not contain any fluorescence, which is not typical for this type of diamond. Even the 2.52 carat Fancy Vivid Green diamond from 2009 had faint fluorescence. This qyality is important to its rarity. A collector will take that into consideration when assessing its potential acquisition....MORE

Here's Diamond Investments blog, they do a decent job of keeping up with the top end of the market:

Bonham’s will offer a rare Blue Diamond at its Hong Kong rare jewels & Jadeite
Dreams Can Come True – With the “Cullinan Dream Diamond”
Christie’s Continues to Unveil Largest Fancy Vivid Color Diamonds at Auction 

If interested see also:

Is the Diamond Cartel Finished?

End of the Oppenheimer Era at DeBeers: Nicky Oppenheimer on What the Family Will Do With the $5.1 Billion
Commodities: Russia's Diamond Hoard Has the Potential to Crush the Diamond Market (or not)
The Next Bauble: Diamond Record Set at Christies Geneva
Paper Diamonds: How Do You Standardize Rocks So They'll Fit Inside An ETF Wrapper?
Diamonds: Have You Been Depressed Since DeBeers Was Delisted? Hangdog Since Harry Winston Split? Cheer Up Bunky, There's Always Alrosa