Doen 925 Silwer juweliersware vervaardigers aangepaste CZ Halo -tennisarmband 925 silwer roes?
Sterling silwer (of 925 silwer) may turn black from the reaction with certain elements in the environment, mostly sulfur but the surface oidation product is very different from those that form on iron and is often just called tarnish which is easily removed with some silver polish and restoring the surface to its original brillance.
Rust that forms on ferrous based materials is not so tightly bonded ot the surface and can destroy the iron frame on an automobile in several years on a wet corrosive environment.