What Is Aluminum Anodize?
It's a very hard coating that is electrochemically grown out of the aluminum. It is great for corrosion resistance because it is so hard, but if it does become dull and need polishing, forget it! It takes on the appearance of the aluminum before it is anodized, i.e. If the aluminum is polished and shiny, the anodize will be shiny. If it is rough, sand cast, the anodize will appear similar. It can also be colored using a million different combinations of dyes.