I have quoted my original response because of CSs reply, which reminded me of ambiguity of you examples. Although I am convinced that I had anwered what you really had in mind, I must agree with CS that example sentence is necessary for the answer.
NOT A TEACHER
('Metallic' would be my choice, since it describes metal metaphorically.(
BTW: Try to use more appropriate title next time. Something like 'metallic or metal' would be better in my opinion.
And welcome to the forums.
Student or Learner