Manufacturers use gold — a versatile and durable precious metal — to produce various products, including writing instruments; such as pencils or pens, eyeglass frames, hollow-ware, jewelry and flatware. Gold plated and gold overlay products, which contain both gold and base metals — such as nickel, copper or zinc — allow consumers access to products with aesthetic virtues of gold, but without the expense. Despite a common relationship to gold, gold plated and gold overlay differ greatly.
Federal identification standards for gold-plated and gold-overlay products are based on the process and materials used during manufacturing. Gold-plating involves the application of gold alloy or gold to non-precious metals; such as copper, zinc, and nickel, using any suitable plating process to achieve even surface distribution of the gold materials. The gold layer must have a significant overall thickness equaling at least 20 millionths of an inch, which is based on the comparative thickness of half a micron of pure gold. In addition, karat designation must be at least 10 karats. Similarly, the gold alloy for gold-overlays must also be no less than 10 karats, but it is applied to the non-precious metal surface using mechanical plating methods; such as welding, brazing, and soldering. While the U.S. Federal Trade Commission does not define a minimum thickness, the gold alloy must account for no less than one-twentieth of the product’s total weight.
Owing to different requirements in calculating acceptable thickness of the gold or gold alloy coatings, gold-plated and gold-overlay products vary in the ability to endure the passage of time. The thinness of gold-plating makes it vulnerable to deterioration, due to a susceptibility to friction, which can result in a gradual deterioration of the gold coating. While gold-overlay with a lower gold-to-metal content ratio may also show the signs of wear sooner than those with a higher ratio, manufacturer’s labeling of these ratios allows consumers to more easily discern the comparative durability of the product. An overall comparison of durability in gold-plated and gold-overlay indicates added longevity for gold-overlay products, as compared to those designated as gold-plated.
While gold-plated and gold-overlay products have similar minimum requirements on karat designation, the difference in methods used to calculate the lowest allowable proportion of gold to base metal contribute to disparities in quality, as well as strength. In determining the amount of gold-based on thickness of coating, gold-plated products often contain less gold than gold-overlay. The lower proportion of gold results in accelerated deterioration, with the gold-plating becoming scratched and worn, cheapening the appearance and undermining quality.
Differences in the pricing of gold-plated and gold-overlay result from variables related to construction. Strength, quality, and the ratio of gold content are all factors in determining value. For these reasons, gold-overlay products are priced higher than gold-plated. The ability of gold-overlay to withstand frequent use and environmental factors, such as natural skin salt — which can eat away at the surface of gold-plated products — results in higher prices, but a less frequent need for replacement.
References and ResourcesFederal Trade Commission: Guides for the Jewelry, Precious Metals, and Pewter Industries
Gem Fashion: Gold Plated, Gold Filled, and Vermeil Jewelry