Derek Howe
That's not gold, It's Kryptonite! RUN SUPERMAN RUN!!!
Stratosfire
Now, look, I don't mean to be pedantic or anything, but the color of gold... is gold. That's why it's called gold. What YOU have discovered, if it has a name, is some...Green.
Bob Stuart
Aluminum anodyzing is not a film. It is a porous, but thickened layer of aluminum oxide (sapphire) with a penetrating dye if color is wanted.
warren52nz
And now the team is working on how to make diamonds look like glass. 8^)
joez
Careful Bob. Anodize isn't saphhire but a hydrated oxide of aluminum. We denote sapphire and ruby as different gems though they are single crystals of aluminum oxide with different impurities to give color. Gold can also look green if it's very very thin. Noticed this when gold coating electron microscope samples years back. Maybe some optics expert/nano expert can comment on that. Have to wonder if each metal has it's own characteristic color palette available.
solutions4circuits
An interference filter...big woop. Besides, just TRY and give her a GREEN ring, ya boffins
Gregg Eshelman
NOVA Science Now just had a show on this tonight, making things smaller. It explained why gold makes red glass. Nanoparticles. Get particles of gold small enough and they don't reflect yellow light but still reflect red light. Alter the surface structure of gold just right and the spectrum of light it reflects best is altered. The problem with a technique like this on a soft metal is it won't be damage resistant. Dents and scratches will obliterate the micro patterns and reflect the natural yellow color of gold. Canada's mint already used a process like this to impress holograms onto the surface of .9999 fine gold coins. Regular .999 fine gold wasn't soft enough. Don't touch them, the oil from your fingers could fill in the micro patterns. Getting them clean without wrecking the hologram, not easy.
D-man
This is just palin stupid. This is first of all a "technology" well known from nature. Butterflies wings appear colored due to sub-wavelength patterns. People have also utilized that by molding metals from actual butterfly wings. And it has been done by nano lithography without the use of actual butterfly wings. One applicaion close to commercial use is the black silicon used to enhance efficiency of solar cells. In that case silicon is patterned with sub-wavelength patterns to reduce reflections to a minimum. And due to that the otherways metallic silvery look of silicon becomes black since it is reflecting a minimum amount of light. So good luck with that patent.... unless it is a patent for the method of producing this for commercial applications.
Charles Bosse
Oxide layers can be used to create colour in many metals. The technique above could make coins hard to replicate, but would require some protection against wear, and would have to be easy to distinguish from other cheaper techniques that could be used for forgery.
Gregg Eshelman
Gold doesn't oxidize, which is one of the reason's it has been a prized metal for thousands of years.