Australian jewellers Noble & Precious specialise in tarnish-free jewellery. It also uses processes that are friendly to the environment. 

Noble & Precious uses marine grade biodegradable stainless steel as the base for their design.

“This is key, as it’s one of only a few metals that are highly durable but also corrosion and rust resistant,” explains Noble & Precious founder, Georgia Antill. 

“This means it won’t erode from the inside when exposed to water, skin, creams, sweat or perfumes, keeping the 18k gold exterior completely intact — even if you shower or swim in it.”

Read full article here: https://www.marieclaire.com.au/fashion/why-does-jewellery-turn-green/