There are always a lot of questions about Gold filled, Gold Plated and Vermeil jewelry - which is the best quality and why?
Well the answer is, it depends on your preference and the price point you're willing to pay.
The simple math is, the more gold, the better craftsmanship and the higher quality the base metal the price increases.
Gold plated jewelry can be made with any base metal (Brass, Stainless Steel or Copper) with a thin layer of gold - 14K, 18K, 24K. The base material is dipped into an electroplating solution bath with a lump of solid gold. The technique deposits a thin layer of gold on the base metal.
Gold filled jewelry is usually made with a Brass or Copper base and is made by mechanically bonding gold sheets to it. Because more gold is used during this technique it results in a quality that is less likely to tarnish.
Vermeil jewelry is gold plated but with a Sterling Silver base. However, in order to call it Vermeil there must be at least 2.5 microns of gold.