Because pure silver or fine silver is quite soft and very malleable it can be easily damaged. Thus it is mixed with other metals to produce a stronger product called Sterling Silver. Sterling Silver is usually made of 92.5% silver and 7.5% copper. The copper component can be exchanged with any other material but copper has been proven to improve silvers hardness and durability without affecting its colour.
Avoid exposing silver jewellery to chemicals and clean silver jewellery regularly to prevent build up of patina.