Why do we value diamonds?

[Soapy Sam]

According to a friend of a friend an engagement fell apart once when the woman found out the diamond in her ring was synthetic and not mined out of the ground. Her fiance was able to do this because he had a friend that worked with synthetic diamonds so he had a jeweler put it in. He didn't lie about it either he just didn't say anything to see if she would notice. Then when he did break the news to her she freaked out and claimed he didn't actually love her.

Or so the story went.

Unlikely. A synthetic diamond of sufficient size and quality to be cut and mounted as a gem would cost rather more than a precut natural stone of the same size. More trouble than it would be worth.

 

[23_Tauri]

Unlikely. A synthetic diamond of sufficient size and quality to be cut and mounted as a gem would cost rather more than a precut natural stone of the same size. More trouble than it would be worth.

So the fake version would be more expensive and more trouble to execute, and therefore much less likely. A bit like making up a story that we went to the moon, compared with actually going to the moon.

 

[ben m]

Unlikely. A synthetic diamond of sufficient size and quality to be cut and mounted as a gem would cost rather more than a precut natural stone of the same size. More trouble than it would be worth.

I'm don't think that is true. Synthetic diamonds already exist and are cheaper than mined diamonds---de Beers is worried about them, and is trying to convince people that diamond cachet only attaches to natural diamonds.

 

[Modified]

I'm don't think that is true. Synthetic diamonds already exist and are cheaper than mined diamonds---de Beers is worried about them, and is trying to convince people that diamond cachet only attaches to natural diamonds.

You are correct. I live a few miles from Gemesis. They crank out 3 carat yellows at about 1/4 the cost of naturals (other colors too, but yellow is the biggest cost difference).

 

[mrgrouch]

as a stone carver diamonds are very valuable to me in the form of cutting, grinding and abrasive tools. other than that, never seen one up close, but i guess people like them because they're shiny... we’re simple like that, the fact that we like them makes them expensive and the more expensive things are the more we seem to like want them… funny aren’t we?

cheers

 

[Dinwar]

Actually, diamonds aren't that shiny. They aren't very reflective--transparent minerals can't be. What they are is refractive, meaning they can split the light into various colors and give off a sparkle. Of course, glass prisms do the exact some thing...

 

[Ziggurat]

Actually, diamonds aren't that shiny. They aren't very reflective--transparent minerals can't be. What they are is refractive, meaning they can split the light into various colors and give off a sparkle. Of course, glass prisms do the exact some thing...

That's not right. First off, refractive really just means it slows down light, which makes light bend when it hits the surface at an angle. The quality you are thinking of (having different indexes of refraction for different wavelength, thus "splitting" colors) is dispersion.

Secondly, diamond is both very dispersive and refractive.

And third, you're wrong about transparent materials not being reflective. They can be very reflective. The reflection just doesn't take place at the external surface, but the internal surface. The high index of refraction of diamond means that total internal reflection occurs over a very wide range of angle. Diamonds are cut in order to try to maximize internal reflection from their bottom facets, so that light which enters the top of the diamond will be reflected off the bottom and back out the top. So reflection is very much part of the "sparkle" of diamonds.

 

[technoextreme]

Actually, diamonds aren't that shiny. They aren't very reflective--transparent minerals can't be. What they are is refractive, meaning they can split the light into various colors and give off a sparkle. Of course, glass prisms do the exact some thing...

Actually, they don't. Depending on the wavelength that you are working with and the applications that you need you might have to use diamond instead of a glass prism. Its a matter of application.
EDIT:
Mind you I'm thinking of industrial applications.

 

[Dinwar]

Fair enough, Ziggurat. Never liked petrology anyway. What I was getting at is that diamonds aren't reflective on the surface, the way that, for example, gallena, pyrite, gold, and those sorts of things are; it needs to be cut to show any light. But that's true of many gemstones, so it's not really an important point.

 

[Doghouse Reilly]

I find this one disturbing. It looks like a Salvador Dali painting: her face is fairly normal (but still a little creepy), but her hair is like those melting clocks. It should not exist in our reality.

It is a Salvador Dali painting, commissioned by DeBeers. It says so at the bottom of the ad.

 

[Doghouse Reilly]

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