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 more tarnish resistant than plated items.  People who can wear gold can wear gold filled without worries of any allergic reaction to the jewelry. 

Regulation:  Gold filled items are regulated.  These items are therefore so much better then gold plated which has no regulations at all.  Gold filled jewelry is made from solid gold and filled with other alloys such as rhodium (a member of the platinum family), brass, and sterling silver.  Gold filled wears, looks and lasts almost like solid gold because its outer surface IS solid gold.  Everything you can see and touch is pure gold.  In the jewelry industry the quantity of gold must be at least 1/20th by weight of the total product.

Lifetime Products:  Gold-Filled items are generally considered lifetime products, and the gold layer will not wear off, as it will in electroplated products. 

Caring for Gold Filled:  Caring for Gold Filled items is as easy as caring for any gold jewelry. 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 jewelry polishing cloth.