What is dark aluminum? It appears to be the type used in flash powders, but how is it different from "regular" aluminum?

 

http://www.skylighter.com/mall/chemicals.asp

 

The link has some down a little on the page.

Well at least it's very, very fine but that doesn't really account for the color. Might be something used in the manufacturing process... perhaps carbon?

I was thinking that (since it was indicated for flash powders) that it either had some sort of "activating" agent the would somehow make it easier to get through the Al2O3 layer on the grains, or perhaps the oxide was somehow different from normal aluminum oxide.

i think ultrafine aluminium powder is black. things tend to change colour if you have a really really fine powder(like 100 or so atoms per grain)

that makes sense...thanks!

its also interesting to note that gold turns purple when made into a really fine powder.

 

damn gold just has to be the odd one out ALL the time.

Are there any interesting effects to note with copper? It's another one of those odd ones out, in color at least.

Copper tends to turn more pinkish when its really fine in my expierence, but even finer it may be a different color