[willvarfar]

> These diamonds were all of a uniform size and shape and were dubbed 'Silver Bears'. While DeBeers could not understand how the Soviets were producing such a large quantity of gem diamonds of such uniform size, and supposedly from one mine that by DeBeers surveys should not be capable of such diamond production, they were, nevertheless, pressured to purchase them all lest the Soviets simply dump the diamonds on the open market, thus flooding it and bringing down diamond prices.

What's the speculation as to their surprising abundance and uniformity?

[ljoshua]

I was curious about that particular aspect as well. A little Googling brought me to this rather interesting account of Silver Bears and the market forces at play:

http://www.edwardjayepstein.com/diamond/chap17.htm

(tl;dr: though unconfirmed a noted diamond expert believed the Soviets had created a diamond cutting machine instead of relying on human cutters, though others disputed the idea.)

[milcron]

It sounds as though they were creating gem-quality synthetic diamonds but kept it on the down-low, and used their Siberian mines as cover.

[ericfranklin]

Even today there are only a couple places in the former Soviet Union that can grow gem-quality synthetic white diamonds. Their production numbers are far less than the output of a single mine, and the results are still rather random. Prior to 2004 or so, the only synthetic diamonds that could be produced commercially were colored and primarily industrial-grade.

[milcron]

Well, I say "gem-quality" because the article did, but it also points out that the diamonds were a greenish color, and incredibly consistent in size and quality.

When DeBeers finally got a 20-minute tour of the Siberian mine, far less earth had been excavated than they expected for the number of diamonds that the USSR sold.

There are many additional circumstantial details in the article.

[atemerev]

Doubtful, for several reasons:

1) Synthetic colorless gem-grade diamonds are difficult to make (they can be produced today, about 2-3 times cheaper than natural diamonds, but in small quantities -- and synthetic industrial-grade diamonds are also quite profitable, with significantly larger and accessible market -- but much easier to create).

2) Synthetic diamonds are relatively easy to identify (with microscope and ultraviolet light source)

3) Even today, Russian-sourced gem grade diamonds are somewhat less diverse in size and quality than their non-Russian counterparts -- and their provenance is well documented.

[tastytang]

Possibly these unusual diamonds were not mined nor manufactured, but were the result of a meteor impact?

http://www.dailymail.co.uk/news/article-2204566/Russia-diamo...

[nthcolumn]

Someone told me about this in 2009. I do not know if it is just a rumor. We were in a piano bar in the old town in Zuerich. I did not know them but they were serious people who lead interesting enough lives not to have to make up stories. Although now I see Daily Mail I am beginning to doubt. He said they are all huge, same in size but hard to work and that there was a 'mother' one which was enormous. His friend sang 'Simply the Best' for Putin. Is it true?

[dankohn1]

I remember hearing a story about diamond polishing methods in use right after the collapse of the Soviet Union where the resulting diamonds had a lower value than their inputs. I've used the metaphor in programming and management of dealing with value-subtracting workers.

[jordanb]

This was a criticism of the late-stage soviet economy: Taking perfectly good trees and turning them into useless plywood. Perfectly good wool gets turned into sweaters so awful even Soviet citizens won't wear them, etc.

Francis Spufford's Red Plenty gets into that, and on the rapidly diminishing returns on capital investment in general in the soviet economy in the 1970s-80s.

[mirimir]

Maybe the Soviets stockpiled these diamonds for some years, before developing a relationship with DeBeers.

[ghostly_s]

The general opinion is this is a synthetic diamond laundering operation. Synthetic diamonds are of course chemically identical to natural, but natural diamonds still fetch a higher price.

[cr0sh]

> The general opinion is this is a synthetic diamond laundering operation.

If this is true, then the Soviet Union must have come up with an alternate method to produce "tons" of these high quality, large diamonds long before anyone else:

https://en.wikipedia.org/wiki/Synthetic_diamond

The two methods then known to make synthetic diamonds, were only useful for industrial diamond purposes, if I'm reading that correctly. It seems like another alternative process wasn't created until the 1990s. It also seems like none of these (?) known processes are useful for gem quality diamonds, or if they are, they can't make such diamonds of large size in large quantities.

If the then-Soviets had this technology - and still have it - it would be a massive disrupter to the entire diamond trade business. I would imagine that even for industrial diamonds, it would still cause problems (you know, problems like lower prices and better availability).

[ericfranklin]

Correct. The Soviet technology for growing diamonds is HPHT (high pressure high temperature). There are a handful of known producers and research facilities in the former Soviet Union that can grow diamonds, but all using HPHT. These were all industrial grade until the late 90s-early 00s, and colorless diamonds did not consistently grow with this technology for several more years.

The other technology you mention is CVD (chemical vapor deposition), which was not developed in Russia, and was not commercially viable for gem-quality diamonds until the last decade either.

[BoiledCabbage]

> These were all industrial grade until the late 90s-early 00s

I believe the point being made is that the only ones publically admitted to being lab made were the industrial grade. The lab made gem grade were made to look like mined stones. The belief is the Soviets kept this a closely guarded secret because it was very profitable for them.

[mustacheemperor]

Do you have a source for that statement? If I'm not mistaken synthetic diamonds are almost always detectable by experienced gemologists (like the ones working at Debeers, presumably), and the timeline of synthetic diamond technology wouldn't line up either.

[ericfranklin]

Major gemological labs can certainly identify a diamond's origin (mined or grown). There are many characteristics that can identify origin, and color or clarity is rarely used as the conclusive indicator. Here is a semi-recent study of synthetic diamonds from my company: https://www.gia.edu/gems-gemology/spring-2014-ulrika-hpht-sy...

You are right though, gem-quality synthetic diamond technology didn't come around for several decades after this mine started producing.

[mohaine]

Last I heard for the grown diamonds it was only because the grown ones have perfect clarity and color which is never the case for natural ones. So the price goes up for clarity and color until it hits perfect then it falls back to synthetic diamond prices.

If a synthetic version is better then the natural version can you still call it synthetic?

[mobilefriendly]

No you call it curated.

[arm85]

https://www.wired.com/2003/09/diamond/

"A few hours later, Clarke was looking at a blueprint for an 8,000-pound machine that used hydraulics and electricity to focus increasing amounts of pressure and heat on the core of a sphere. The device, he was told, re-created the conditions 100 miles below Earth's surface, where diamonds form. Put a sliver of a diamond in the core, inject some carbon, and voil�, a larger diamond will grow around the sliver."

[gambiting]

I thought there were ways to tell synthetic from natural? Surely DeBeers were particularly interested in discrediting Soviet diamonds and if they could find proof that those were indeed synthetic, they would have used it?

[ghostly_s]

Not sure, I read an article some years ago that said as much. I expect you could identify natural diamonds by impurities and subtle imperfections in the cut, but I don't know how you could conclusively prove a too-perfect diamond was synthetic.

[gambiting]

According to this article[0] it is possible, but it's not like there's one 100% accurate method - but a skilled gemologist should be able to identify a synthetic diamond:

https://www.gia.edu/sites/Satellite?c=Page&childpagename=GIA...

[ridgeguy]

Yes, it's possible with a high degree of confidence to distinguish natural from synthetic diamonds and for synthetics, to determine which method (HPHT or CVD) was used to make them.

The IIDGR [1] company makes a series of devices (DiamondSure, DiamondView and DiamondPlus) that will indicate whether a diamond is a natural (and if so, of what type), or flag it for further characterization. One system will flag type IIa naturals for further analysis, as they resemble the best of CVD synthetic diamonds. Microscopy + (IR, fluorescence, and photoluminescence) spectroscopy distinguish a stone's origin to high confidence. Even though the best CVD stones have far lower impurities than the best naturals, they have internal strain patterns (optical birefringence) that can be diagnostic.

Most jewelers don't have these machines, but they are available as a service.

Faceted CVD stones have been seen up to 5 carats [2] and 10 carat stones made by HPHT are known [3]

[1] https://www.iidgr.com [2] https://www.gia.edu/gems-gemology/winter-2016-labnotes-CVD-s... [3] https://www.gia.edu/gems-gemology/winter-2016-labnotes-blue-...

[willvarfar]

I recall watching a documentary where the reporters got diamond merchants to test some diamonds. Many of the synthetics were easily spotted but one - from a new technique or something - was only spotted because it was "too pure".

[ericfranklin]

The testers a typical jeweler or diamond merchant might use only identify between diamond, cubic zirconia or moissanite. They do not identify origin of a diamond.

The testers that can identify a diamond's origin are quite expensive and usually only found at major gemological labs.

All synthetic white diamonds are "Type IIa" (no or trace amounts of nitrogen) while only 1-2% of mined diamonds are IIa. 97% of mined diamonds are "Type Ia" (clusters of nitrogen). It is possible that is what they were referring to about purity, but the amount of nitrogen is not a definitive indicator of origin.

[jghn]

Perhaps the same documentary, but a while back I saw something where the latest techniques were easy to spot for being too good. But then they showed a new technique being developed that was able to inject natural seeming imperfections. The show claimed that this was the impetus for DeBeers laser etching their mark on diamonds as they had no other way of detecting the difference.

This was a while ago though so I'd imagine the cat & mouse game has evolved for both sides.

[Alupis]

That's how all synthetics are identified... natural diamonds all contain impurities from the material they were formed near/in.

It's sort of funny in a way... impure diamonds are worth more than pure diamonds... but then again, none of them would be worth much at all if DeBeers didn't control the release into the market (diamonds are not rare at all, and therefore only valuable due to artificial scarcity).

[gozur88]

Seems like you ought to be able to create a process that adds impurities that mimic natural diamonds.