Re: OT: Marcury has a layer of diamond 10 miles thick, NASA spacecraft finds

By the time we can mine Mercury, we will be able to make diamonds as cheap as water anyway.

John ;-#)#

You think the price of water will have gone up by that much?

Diamond, like gold, is valuable because it's rare. Accessing cubic miles of diamonds would trash its value.

Diamonds aren't really all *that* rare - a cartel controls production and marketing. They were bricking themselves when synthetic gem quality diamonds became possible by CVD. You can tell the difference with a loupe even now and particularly in the early days since they tended to have nitrogen impurities and were yellow. The best labs have got remarkably good at it in the past couple of decades!

"Diamonds are forever" isn't quite true either. If you get one red hot and then drop it into a jar of oxygen it burns rather brightly.

Which would be good, because it's useful!

Jeroen Belleman

Hey! Be nice to me, I sell the jukeboxes that take your records!

(ducking)

Energy available to the human race seems to be growing around

John ;-#)#

Wrong. Diamond is light, hard, strong and has very high thermal conductivity. You can buy synthetic diamond heat-sinks right now.

Some collectors will pay silly money for anything rare enough. The main use for moon rock was to determine the age of the Moon or rather the time of last melting of the pieces of it that they brought back.

I reckon less than 1kg all up of moon rock was actually used destructively in this way - the rest is sat in museum cabinets (and in a few professors trophy cabinets). Looks very much like terrestrial basalt to the trained and untrained eye alike (think tarmac carpark rock).

Iron meteorites with huge crystals in are much harder to fake.

Diamonds are only valuable because of the De Beers convincing the women they need them. Almost all diamonds used to go through them and they would only let a few out and if you tried your own mine and a store bought some from you the De Beers would cut them off.

They are like paint. Anyone can get paint and put it on a canvas but if you have the big name you get thousands or millions for the painting. Diamonds can be cut and put into jewelry as an art form.

Would love to have some diamond (man-made is fine) heat sink insulator material !

boB

If you mean an insulator between a power transistor and an aluminum or copper heat sink, a thin aluminum nitride insulator would be almost as good as diamond. Or hard anodize.

Really using the heat sink would require lateral heat spreading, namely a big thick slab of diamond.

Somebody hasn't heard of industrial diamonds.

Yes there are plenty of industrial diamonds and they are almost worthless compaired to the jewelry quality.

In not too long ago time there has been a way to make them instead of mined diamonds.

Diamonds are rated by how well they can be converted to jewel quality. The 4 C's. Color cut clairty carat. If they do not measure up they go to the industrial bin and are almost worthless.

John, this would be used as a lower thermal resistance insulated interface from case to heat sink. I wonder if you still need to use the white bird s*it on that interface ?

boB

Silicone grease makes a huge difference in thermal conductivity, especially if the mating parts are not optically flat.

A typical TO-220 mosfet tab can be bowed by a couple of mils, and heat sinks are usually extruded, not very flat. Air gaps are rotten heat conductors.

Given some grease, keep the insulator thin.

Polycrystalline diamond is crazy expensive.

One trick is to bolt a transistor directly to a copper block, to spread the heat footprint, and insulate that from the main heat sink.

Or just parallel a few fets to spread the heat around.

To jewellers. We mine 27 metric tons of diamonds, and make 900 metric tons of synthetic diamonds,essentially all for industrial applications.

We wouldn't be doing that if industrial diamonds were "almost worthless". The fact the gem-quality diamonds can be sold for a lot more money than industrial diamonds doesn't make industrial diamonds worthless - if gem-quality diamonds fell out of fashion we'd still be digging up and making a lot of industrial diamonds.

From what I could find in a quick search the industrial diamonds are only about 10 to 20 dollars per carat vers the seveal thousand dollars the jewel quality ones would cost. That is where I base my 'worthless' price at. Industry still uses a lot of them in many processes so they are valuable for use but worthless for money cost.

Cheap isn't the same as worthless.

Nothing would stop working if the gemstone supply was cut off, but industrial diamonds keep industry working.

The gemstone business is a luxury trade that piggy-backs off the industrial diamond supply chain.

Diamond mining supports several rather unpleasant regimes

My bad choice of words. I should have said something more like they are not worth much money. They are very useful in industry, just do not cost anything at all like the jewelery ones.

Years ago I had an uncle that worked for a brick company and he used a saw to cut the bricks for samples. He had saved a jar full of diamonds that came off the saw blades. Thought he had some big money comming to him. Found out that that whole jar would only sell for a few dollars.