Gold Filled and Gold Plated Process and Gold Karat Definition

The term gold-filled refers to the manufacturing process in which a sheet of base metal, usually brass, is mechanically bonded with thinner sheets of gold. A "sandwich" is formed by mechanically bonding a layer of gold on both sides of brass. This "sandwich" is then cold worked by rolling until a much thinner gauge metal is achieved. Products are then formed or die-struck from this layered material.

When a layer of gold is affixed on all surfaces by any mechanical means and the weight of the gold is a minimum of 1/20 of the total weight of the metal in the article, it may be marked Gold-Filled (GF). The quality of the gold used is typically 10, 12 or 14 karat gold with 10 karat being minimum. Hallmarking would look like “10K GF” or “14K GF”. Yellow gold-filled or white gold-filled simply indicates the color of the karat gold used in the making of the gold-filled product.

The terms “Rolled Gold Plate” and “Gold Overlay” refer to the same bonding process; however, the weight of karat gold is less than 1/20 but not less than 1/40 of total weight of metal.  Hallmarking would look like “1/30 12K R.G.P”, “1/40 10K Gold Overlay”.

Gold Plated

When a product is referred to as gold, rhodium, or nickel-plated, this indicates that it has been electroplated with a thin layer of that particular metal. An article of jewelry is Gold-Plated when gold is electroplated or mechanically sheathed with a mini­mum thickness of 1/2 micron (20 millionths of an inch) of fine gold. The quality of the gold used is typically 10, 12, or 14 karat. The karat quality of the gold plating must be disclosed, and it can be described as 12K Gold Plate or 2μ 12k G.P. for an item plated with two microns of 12 karat gold.

The table below lists all the different plating terms and their associated thicknesses.

Gold Plating	Plating Thickness
Heavy Gold Plated	> 100 Micro-inch (> 2.5 micron)
Gold Plated	> 20 Micro-inch (> 0.5 micron)
Gold Electroplated	> 7 Micro-inch (> 0.175 Micron)
Gold Wash/Flashed	< 7 Micro-inch (< 0.175 Micron)

 

What are gold karat or carat and their differences?

Gold karat refers to the purity or fineness of gold, and it is expressed as a percentage or a number followed by "k" or "kt". The higher the karat, the purer the gold.

Here are the most common gold karat values and their differences:

1. 24 Karat (24k or 24kt): Gold that is 24 karats is considered pure gold, with a gold content of 99.9% or higher. It is the highest level of gold purity and is very soft and malleable, making it less suitable for jewelry that needs to withstand daily wear and tear. 24 karat gold is generally used for investment purposes, bullion, and some specialized jewelry.

2. 22 Karat (22k or 22kt): Gold that is 22 karat has a gold content of 91.7%, with the remaining percentage being made up of other metals, such as copper or silver. 22 karat gold is commonly used in traditional and ethnic jewelry, especially in certain cultures, as it is considered to be a good balance between purity and durability.

3. 18 Karat (18k or 18kt): Gold that is 18 karat has a gold content of 75%, with the remaining percentage being made up of other metals. 18 karat gold is widely used in fine jewelry, as it offers a good combination of gold purity and durability. It is also commonly used for engagement rings, wedding bands, and other high-quality jewelry pieces.

4. 14 Karat (14k or 14kt): Gold that is 14 karat has a gold content of 58.3%, with the remaining percentage being made up of other metals. 14 karat gold is commonly used in a wide range of jewelry, including engagement rings, earrings, necklaces, and bracelets, as it offers a good balance between durability, affordability, and gold content.

5. 10 Karat (10k or 10kt): Gold that is 10 karat has a gold content of 41.7%, with the remaining percentage being made up of other metals. 10 karat gold is the lowest karatage that can legally be sold as gold jewelry in some countries, and it is generally less expensive and less pure compared to higher karat gold. It is commonly used in more affordable jewelry and fashion jewelry.

In summary, gold karat refers to the purity of gold, with higher karat values indicating higher gold content. However, higher karat gold may also be softer and less suitable for certain types of jewelry that require durability. The choice of gold karat for jewelry often depends on personal preference, budget, and the intended use of the jewelry. It's important to understand the differences between gold karats and make an informed decision when purchasing gold jewelry.