Gold Filled

Gold-filled jewellery is composed of a solid layer of gold, which must constitute at least 5% of the item's total weight, mechanically bonded to sterling silver or a base metal. The related terms "rolled gold plate" and "gold overlay" may be used if the layer of gold constitutes less than 5% of the item's weight.

https://en.wikipedia.org/wiki/Gold-filled_jewelry

 

Gold Filled:  Gold filled is an actual layer of gold-pressure bonded to another metal.  Gold filled is not to be confused with gold plating as filled literally has 100% more gold than gold plating.  Gold filled is much more valuable and tarnish resistant.  It does not flake off, rub off or turn colours.  As a matter of fact, anyone who can wear gold can wear gold filled without worries of any allergic reaction to the jewellery.  Gold filled jewellery is an economical alternative to solid gold!

Caring for Gold-Filled:  Caring for Gold Filled items is as easy as caring for any gold jewellery. Simply keep away from chemicals, clean regularly with mildly sudsy water, rinse well and pat dry with a non-scratching cloth. Polish gently with a jewellery polishing cloth.