All silver has a tendency to tarnish over time. Tarnishing naturally occurs because of chemicals in the air, for example sulfur or hydrogen sulfide. Humidity and storing the silver can also tarnish the piece, known as oxidation, which will give the silver a darkish black colour.
Tarnish is most easily removed when it first becomes visible, it can be removed using specialist cleaning treatments available from high street Jewellers or online, @ Allure Accessories we stock only one brand: Talk of the Town.
When cleaning your Jewellery with propriety products always carefully follow the manufacturers instructions and remember to thoroughly rinse the items in warm, fresh running water to remove any residue from the cleaning solutions used.
As a footnote, the very best way to keep your silver jewellery clean is to love it by wearing it often.