The range of alloys used is stunning: weathering steel for patina, marine-grade aluminum for weight savings

https://www.scribd.com/document/1041332768/Customized-Copper-Cupolas-From-Specification-to-Centuries-of-Solution-171009

The series of alloys utilized is magnificent: weathering steel for patina, marine-grade aluminum for weight cost savings, and duplex stainless for deterioration resistance in severe environments.