Holey Gold

.Gold is usually thought of as being a shiny metal -- however, in its [nano]porous form, gold actually appears dull and black. The surfaces of nanoporous gold are rough and the metal loses its shine. Michel Bosman at the A*STAR Institute of Materials Research and Engineering and co-workers have now experimentally demonstrated that the dullness is a consequence of the way incoming light couples to the electrons on the gold surface.

Ok so the A*STAR institute have been looking at gold in its nano-porous form and what they found is that although to the human eye the material looks black, in fact, this is not true and it only appears that way because we are (relatively) far away from it.

In experiments firing an electron beam over nano metal films Bosman and co actually found that both nanoporous gold and silver were actually very colorful when you zoom in on them.

I thought that the picture was pretty fascinating because the colors are very vivid pinks, purples and yellows, which is not something I would have expected. I found it both

beautiful and curious

Source

Originally posted by Lagrimas
because the colors are very vivid pinks, purples and yellows, which is not something I would have expected.

Your expectations were right the first time.
The color image is a completely false color image. They could have tinted them as intensely or as weak as they wished, since all the data really comes out of a scanning electron microscope (which really has no color at all).

Actually, since the color map comes from inferring the color *absorbed* then it would be more correct to say that the colors should be inverted if you wish to image how it would look if you were a hypothetical micro-person standing up close to it.
eg. where the image is violet, one would see yellow.

reply to post by alfa1


Huh so its not colorful? Or it is, but inverted? Im not following.

Ah well, I think its cool that nanogold has light absorbing properties and peculiarities and appears colorful up close, even if no one else does.

reply to post by Lagrimas


For the use of absorbing light, there can be no contenders, no pretenders to the darkest of thrones my friend...

www.popsci.com...

Blacker than the blackest black times infinity.

\m/