The Graphite and the Ebony (Black) are anodized aluminum. This process converts the metal surface into an oxide finish. Unlike paint or plating, this process is fully integrated with the metal so it will not chip or peel. For a colored option, this is the best/safest/most durable out there we know of. Obviously our natural finish (just a polished piece of aluminum) takes it a step further.
As for the the moonstone color (white), the process is an industrial strength coating. The coating is safe per FDA regulations. But upon abuse, it could chip or wear.