Gold-filled jewelry is jewelry composed of a solid layer of gold (typically constituting at least 5% of the item’s total weight) mechanically bonded to a base of either sterling silver or some base metal.  Unlike vermeil and gold plated jewelry, gold filled jewelry has a much thicker layer of gold over the base metal. This makes a big difference in terms of the jewelry’s ability to resist wear and tear long term. 

Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver, by chemical or electro-chemical plating.

Vermeil is plated with 14K-24K gold. This is a good combination for those with allergy to normal, plated jewelry items. The difference between vermeil, and gold-filled, is in the thickness of the gold and the base metal used. In vermeil, the base is sterling silver.  As vermeil jewelry is composed of two precious metals (gold and silver), it’s usually thought of as being closer to fine jewelry and tends to fall under the category “demi-fine.” The higher the karat weight and thickness of the gold layer, the more expensive and valuable the piece will usually be.

PVD stands for Physical Vapour Deposition, and is a vacuum coating process of gold that produces a brilliant decorative and functional finish to the base metal. PVD utilizes a titanium nitride that provides an extremely durable coating. PVD coatings are more resistant to corrosion from sweat and regular wear than gold plating. It's a great choice for people who never take their jewelry off, as it is extremely vibrant and durable for many years. Even big, luxury brands use this process, like Rolex and Cartier.