DeBeers is not in Australia. Here’s some info on the mines in Australia (the Argyle mines comprise almost all of Australian diamond mining):
www.diamonds.net/news/printmsg.asp?msg=2981&search=argyle&nf=0
DeBeers now controls about 60-70% of the world’s rough diamond supply, which is less than it used to control.
Arjuna34
Arjuna34:
**Ummm… wrong some more 
I think the main interest in diamond semiconductors isn’t because of the size of the carbon atom and the silicon atom, but because of the thermal conductivity of diamond.
snip**
So, remembering that diamonds will burn in a pure O2 atmosphere, I looked up “diamond” and “burn” on Google (is there another search engine?) and found this: http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/BDGtext/BDGDmnd.html
All those over-clocking fans may wanna note the 1000C high end for a diamond chip. Yes, that’s three zeroes. Apparently, Ronco plans to break in to the desktop PC market with a model that cooks jerky and rotisserie chicken.
Having recently purchased and engagement ring, I of course looked into diamonds.
I read about black diamonds, and liked the idea, but never saw one. Has anyone seen a black diamond in real life? What do they look like?
What about the good old USA? I recall reading that somewhere in Arkansas, there is a diamond mine. A few investors evaluated the economics of mining the site-I guess back a few years when prices were higher, it almost made sense to do it. Can you imagine Bill Clinton making a deal with deBeers?
I’ve never seen a black diamond IRL (as far as I know). They look a lot like very shiny onyx to me. Here’s a pic. Incidentally, that link mentiones that you can irradiate diamonds to change their color, but I think it can only make them greenish or bluish. I always suspected there was something funny about those cheap teal diamonds that started cropping up a few years ago; they’re off-color stones that have been irradiated.
“The Black Orlov,” eh? I can’t help seeing Rowan Atkinson (as Edmund Blackadder, of course) dressing for a fancy event and, when asked which codpiece he wanted to wear, striking a pose and saying most dramatically “The Black Russian!”
:: blushing :: Ooops. My bad. I guess I’ll check my facts next time before I suggest I know anything about jewelry.
“Domino’s can I help you?”<p>“Yes, I’d like a medium one-topping with half pepperoni and half placenta.”
She’ll always be a Guiness swilling elf to me 
“I guess one person can make a difference, although most of the time they probably shouldn’t.”
I had originally thought that sapphire/ruby/emerald prices dropped appreciably once we managed to make cheap synthetic ones that were indistinguishable from their natural counterparts. If not, that’s quite a testament to the staying power of a “genuine natural ruby” stamp of authenticity. (In the Nova episode on synthetic diamonds, they showed this microscopic “DeBeers 2000” stamp on one genuine diamond. Perhaps that would, indeed, be enough to save DeBeers once synthetic diamonds become indistinguishable from real ones and the patents expire.)
Meanwhile, Jophiel wrote:
According to the Merriam-Webster Online Dictionary ( www.m-w.com ) entry for “emerald”, synthetic green corundum stones are sometimes referred to as “emerald” also, although the proper (first) definition of emerald refers to a beryl stone. I’d have thought that, technically, a green corundum stone (synthetic or not) would be called either a “green ruby” or a “green sapphire”. Plus, aren’t there “pink sapphires”?
The truth, as always, is more complicated than that.
A green corundum is a green sapphire. It shouldn’t be called an emerald by any stretch, but before people got hip to chemical composition of stones they tended to go by color, so a lot of stones were miscategorized. I think there is a well-known “ruby” necklace in a museum that they found out was red spinel (considerably less rare), but I don’t recall the name offhand. There are pink sapphires; I’m not sure exactly how dark a pink the corundum has to be to be called a ruby and not a sapphire. But any color corundum besides red is considered a sapphire (they come in all colors).
People are close to making synthetic diamonds that could fool people into think they’re natural, but there are still some types of natural diamonds that are very hard to duplicate synthetically. There isn’t just one type of “natural” diamond- there are many types of inclusions and natural imperfections. Synthetic diamonds tend to have a different set of imperfections, some of which also appear in natural stones, some of which don’t. Some types of natural imperfections aren’t easily reproduced synthetically (yet), and some are. What could happen is that natural diamonds which are easily verifiable as natural will stay expensive, while natural diamonds that are so similar to synthetics that they’re hard to tell apart might get cheap (or somewhere between synthetic and natural prices). This all assumes, of course, that synthetic diamonds become cheaper to make than natural.
Arjuna34
Gaudere, thank you for the picture of the black diamond! I personally think they look pretty nice. I tried to find one (for the engagement ring), but no luck with local jewelers. I suppose I could have looked on the internet, but something about buying diamonds over the internet struck me as asking to be swindled. (Of course, you have to take whatever a jeweler says on faith anyway.)
I would think you could get a jeweler to get in a black diamond for you, even if s/he didn’t have one in stock. You’d probably need one that has contacts with gem dealers that sell the more obscure stones, though. Get it GIA certified and you’ll have more proof that it’s what it’s supposed to be than a lot of people have for their diamonds.
Crater of Diamonds State Park, Murfesboro, Arkansas. For a small fee, you can camp there and spend your whole day digging for diamonds in the Prairie Creek Lamporite! But only a small bit of it: the rest of the lamporite is owned by an exploration company that is sitting on it. And even if you don’t find diamonds, there’s plenty of olivine (peridot), pyroxene, phlogopite, spinel, etc.
In 2010: Odyssey 2, Arthur C. Clarke speculated that, since heavy elements like carbon would have tended to precipitate down to the center of a forming planet while the Solar System was young, there may be a diamond at Jupiter’s core that’s as big across as the Earth.
Of course, getting it out would prove rather difficult.