I know for a lot of places, Google use fancy algorithms for extracting information about buildings and trees, and those algorithms never cease to amaze me. Anyway, Mirny is clearly not one of these places.
Don't tempt us with interesting details like that and then leave out the name :)
What's the speculation as to their surprising abundance and uniformity?
(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.)
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.
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.
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.
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:
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).
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.
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.
You are right though, gem-quality synthetic diamond technology didn't come around for several decades after this mine started producing.
If a synthetic version is better then the natural version can you still call it synthetic?
"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."
The IIDGR  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  and 10 carat stones made by HPHT are known 
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.
This was a while ago though so I'd imagine the cat & mouse game has evolved for both sides.
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).
Helicopters can't fly over it—the downward force of the air would pull them in.
Thus, two things are happening. First, the warm air rising from the hole is less dense and gives less lift to helicopter rotors than the cooler air it had been flying through. Since the temperature change is extremely abrupt as the helicopter flies over the hole, the pilot may lose a bunch of altitude before managing to adjust the speed enough (read: increase the spin rate of the rotors) to compensate for the loss of lift.
At the same time, the cool air pouring into that hole from all sides is going to create quite a wind shear. If a helicopter loses enough lift to hit the stream of cold air, it could easily be slammed into the side of the borehole before it ever developed enough lift or power to recover.
"They should install wind turbines around the perimeter of the hole and take advantage of it! New form of renewable energy – hole in the ground energy!"
Clearly a form of joke, but im intrigued to know why this won't work. (Or why it could work)
In Europe, most of towns are historic, they're in good places and can take any place in economic system.
In America, there are towns dedicated to mining or specialized farming (rubber?), but they quickly get abandoned when mine is exhausted or the output is no longer needed.
Soviet Union built quite a few towns in remote northern locations, they were way bigger than feasible for mining - like a general purpose settlement. Guess what, now it's hard to rationalize their existence, but people are stuck there and see it as their home. People aren't very mobile in Russia.
I imagine even when diamond mining is over we're going to pretend that this is just another town that can get jobs on its own and it will be held afloat by redistribution. It's going to be pretty miserable place for sure, I imagine.
The conflict in Donbass also has a similar interpretation: coal production there peaked in the late 70 and by the 90 it was an endlessly subsidized rust belt, with a significant minority of the population being born outside Ukraine. It is a backwater hopelessly reliant on outside help, with widespread violent crime, alcoholism, drug use and corruption. It is these rust belts that lower the statistics for the whole Eastern Europe. Young people were leaving it in droves long before the current conflict began.
The disruption by current separatist governments (commanded and supplied by the Russian Federation) have made the decay much quicker - around half the population has left, with a big part of the people remaining being seniors who cross checkpoints to collect their pensions.
You may think it's a backwater but people actually live and work there.
It is largely a statistical illusion - a huge part of Ukrainian economy is in the gray sector. However government transfers, budget spending and industry does show up in statistics.
The two Donbass oblasts actually scored high on GDP per capita, but had much lower quality of life indicators. A large reason for this disparity in income is government transfers, like the big pension and health benefits provided to mine workers. You also had huge indirect transfers like the government propping up failing enterprises and buying production from the regions industrial oligarchs.
BTW, Russia reformed their coal production by closing unprofitable mines and selling the rest. Now producing more coal for less money without subsidies. Ukraine did not and largely kept Soviet mine system intact.
> backwater hopelessly reliant on outside help, with widespread violent crime, alcoholism, drug use and corruption
You have combined "basket of deplorables" reasoning with divisive Ukrainian nationalism to achieve a new low.
A lot has been made about how these people feeling left behind relative to prosperous coastal cities enabled a Trump victory. The trends are of course much older than that.
Anyway, I guess Pennsylvania is habitable when the push comes to shove. Vorkuta, Mirny or Norilsk simply aren't. They're more like Mars bases.
Also, in terms of "Pennsylvania being livable", careful about painting the whole of Pennsylvania with a wide brush. There's an old like about Pennsylvania: it's Philadelphia and Pittsburgh with Alabama in the middle.
From $7,300/person, but you'll need to wait until next year since this year's kicked off today.
They can prop up Stalinism regimes.
They can prop up apartheid.
They can prop up the likes of Mobutu Sese Seko.