Chains as many other products in the jewellery trade are produced in various metals; Platinum, Gold and Silver, these are well recognized!
Silver chains must consist of at least 92% fine silver, often plated with a rhodium layer to bring their extra shine. Rolled Gold chains are silver based, layered with 18 karat gold. Gold Filled chains, also silver based but made by joining layers of gold alloy.
Brass is the most used alloy for higher quality products, these are then electro plated with gold or silver layers.