George Orwell. (2025, February 24). Wikiquote. Retrieved 18:47, March 2, 2025 from https://en.wikiquote.org/w/index.php?title=George_Orwell&oldid=3673369.
Some metals, such as copper and gold, have electronic interband transitions in the visible range, whereby specific light energies (colors) are absorbed, yielding their distinct color.