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Diamonds

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eggshaped
52486.  Fri Feb 17, 2006 1:05 pm Reply with quote

Question: Where is the largest known diamond kept?

Forfeit: The star of Africa, kept in the crown jewels

Answer: Inside the star “Lucy” which is, in turn, found in the constellation Centaurus.

The star “Lucy” in the constellation of Centaurus got its nickname from the Beatles classic Lucy in the Sky with Diamonds, but it is more technically known as the white dwarf BPM 37093.

By measuring the pulses that this star gives out, scientists have been able to deduce that its interior is actually an enormous diamond, 4000 km across and measuring ten billion trillion trillion carats.

In millions of years to come, astronomers expect that the Sun itself will turn into a similar white dwarf, its core crystallising into another huge diamond.

http://cfa-www.harvard.edu/press/pr0407.html

 
eggshaped
52489.  Fri Feb 17, 2006 1:18 pm Reply with quote

Curses, ciggiwink's beaten me to it by a paltry 16 months.

post 9758

 
Flash
52598.  Fri Feb 17, 2006 7:08 pm Reply with quote

Ah yes - Planet Bling we called it, back then.

 
Flash
60375.  Fri Mar 17, 2006 6:28 am Reply with quote

Diamonds are 'hard' but not particularly 'tough' - toughness being the capacity to resist breakage from an impact.

In theory diamonds will eventually decay into graphite, but very slowly; the time taken would (perhaps) be longer than the life of the Universe (a statement which begs an obvious question, but let's not get into that).

Diamonds' values are established on the basis of the 4 Cs: carats, clarity, colour and cut - which together give the 5th C, cost. The carat is a measure of mass: 200 milligrams, .007 of an ounce.

The Cullinan Diamond is the biggest gem-quality uncut diamond found to date, and the Great Star of Africa which was cut from it was the biggest cut diamond until 1985 when it was surpassed by the Golden Jubilee.

De Beers (founded by Cecil Rhodes - the de Beer brothers owned the land on which diamonds were found in South Africa; they sold it for £6,300) still controls over half the diamond trade. Retail pricing is completely rigged by them (the scarcity of stones on the market is an artificial creation), and their advertising/marketing since 1938 is regarded as one of the most successful campaigns ever, in particular for the slogan 'a diamond is forever'. Prior to this campaign, no one stone was particularly associated with engagement rings.

The campaign was mould-breaking in a number of ways: use of product placement, enlisting Royalty, and particularly for the fact that it was all generic - no brand name was promoted, just the ownership of diamonds. One of the effects of the slogan about a diamond being 'forever' has been to create a strong presumption that diamonds should be kept for good and not resold - so there's no second-hand market to speak of, which is a big help to De Beers in controlling supply.

De Beers' labourers in the 19th century were prisoners; the company built and ran the prisons and the South African state filled them with prisoners - 10,000 at a time.

All from the wiki and its links.

 
Flash
60376.  Fri Mar 17, 2006 6:32 am Reply with quote

Possible links to Digbys, Dulux, and Dogs, for the success of the advertising campaign.

 
Flash
60380.  Fri Mar 17, 2006 6:37 am Reply with quote

Might this work?

Question: What are diamonds?

Forfeits: Forever, Rare, Hardest material
Answer: Crystalline carbon

With notes re famous diamonds, Planet Bling, people having their ashes turned into diamonds, De Beers and that advertising campaign.

 
eggshaped
60383.  Fri Mar 17, 2006 6:43 am Reply with quote

You do run the risk of some smart-arse saying "carbon" straight away.

 
Flash
60384.  Fri Mar 17, 2006 6:43 am Reply with quote

Tiffany & Co are trying to repeat the success of the diamond campaign with a stone called tanzanite. Only one source of the blue stone is known (in Tanzania) and the supply is predicted to be exhausted in a decade; they're trying to position it as a 'birth' stone which should be given to every new-born baby. In this case the scarcity is genuine, and the stones are priced at around $800 a carat.

 
Flash
60385.  Fri Mar 17, 2006 6:46 am Reply with quote

eggshaped wrote:
You do run the risk of some smart-arse saying "carbon" straight away.

True. Maybe, then:

Q: Diamonds are crystalline carbon. What else are they?

F: As above
A: A frightful con

 
Gray
60392.  Fri Mar 17, 2006 7:01 am Reply with quote

Graphite is more stable that diamond (at room temperature), which is why it's said that it could 'decay' into it. Decay is all about differential stability.

However, in order to reach this lower 'valley', a diamond has to first get over an energy 'mountain' - i.e. get enough energy to release the carbon atoms from their bonds. Only then will it slide down the 'other side' into graphite valley.

 
Flash
60511.  Fri Mar 17, 2006 12:26 pm Reply with quote

The diamond market is currently booming, mainly because of China. Ten years ago engagement rings were unknown there, but now 80% of urban Chinese brides get them, according to de Beers MD Gareth Penny.

 
Flash
63355.  Sun Apr 02, 2006 7:00 am Reply with quote

Diamonds are formed in geological features called 'kimberlite pipes'. There's an explosion deep inside the Earth (200km down) which fires a cannonball of magma towards the surface at supersonic speed. This is a totally random event - a kimberlite pipe could explode under your feet as you read this. They bring up various bits & pieces that aren't normally found on the surface; in about 1 pipe in 100 that includes diamonds. A chunk of carbon has to shoot up at just the right speed and cool down quickly enough to become a diamond.

One such pipe in South Africa made that country the biggest source of diamonds in the World, but there may well be others undiscovered. In North-Eastern Indiana, for example, very big diamonds are sometimes found, but no-one knows where they come from. The pipe could be under the Great Lakes, or hidden in some other way.

s: Bryson's Short History

 

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