The variety of alloys utilized is stunning: weathering steel for patina, marine-grade light weight aluminum for weight savings
https://telegra.ph/Crowning-the-Roofline-Copper-Finials-that-Confirm-Their-Value-Over-a-Century-07-03
The series of alloys made use of is spectacular: weathering steel for aging, marine-grade aluminum for weight financial savings, and duplex stainless for deterioration resistance in rough climates.