Copper is next mentioned in connection with the Tabernacle, the temporary tent or dwelling place for God during the wilderness wandering of the Israelites. All the metals used in the Tabernacle have symbolic significance. No iron was used but gold, copper, and silver appear in numerous places. Gold, an element of great value, represents the divine nature, incorruptible and likewise of great value. Silver represents truth. Copper, which superficially resembles gold, represents perfect human nature. This is the nature of man who was created in the image of God. This symbolism is repeated numerous times in Scripture.
-- "Iron and Copper"
For historical reasons, Copper is also the symbol of Venus.
Adaptability, due to Copper's ductility.