I never knew the difference between gold-filled and gold-plated until I started making sea glass jewelry. Come to find out, gold-filled is much more valuable!
Gold-filled jewelry has a much thicker layer of gold (it has to be 1/20th of the weight of the piece). The gold is applied through a mechanical process of bonding and heating. Gold-filled jewelry is less prone to tarnishing.
I absolutely LOVE the look of a perfect piece of sea glass hanging from a beautiful gold-filled chain. Coastal Charms uses only gold-filled chains for our sea glass jewelry.
Gold-plated jewelry is less expensive, because there is only a very thin film of gold on the piece. It is a base metal which after several processes is dipped into a solution that contains gold. An electric current is applied and the reaction causes gold to be deposited. Gold-plated is more prone to tarnishing and easier to rub off.
Always put on your sea glass jewelry AFTER applying lotions, perfumes, hair sprays, etc... and they have had a chance to be absorbed by the skin. These chemicals can alter your jewelry.
If you wipe your jewelry with a soft cloth before storing, and you keep it away from chemicals, it should last a long time!