"Aluminium finish" refers to the appearance or outer coating that makes something, usually an object or surface, look like it is made of aluminium even if it is not. Full definition
Once again, I notice that the brushed aluminium finish on the back actually offers some extra grip to prevent it from sliding out of my hand. (pokde.net)
It's a gorgeous glossy flat disc with a metallic aluminium finish around the edges. (pocket-lint.com)
Turning towards the left shows a power / lock key in aluminium finish. (techone3.in)