A lustrous, silver-white, nonmagnetic, lightweight metal which is very malleable; has good thermal and electrical conductivity; a good reflector of both heat and light. In construction, most aluminum is used in alloy form because of added strength; further strengthened by heat treatment; used in extrusions, castings, and sheets. Excellent resistance to oxidation; often anodized for better corrosion resistance, surface hardness, and/or architectural color requirements.