Different Types of Gold Coatings
Gold coating or plating is a procedure where a thin layer of gold is welded onto a base metal. Coating is very common in the jewellery industry, with gold and rhodium being the two popular metals to be coated on other metals. An Italian chemist named Luigi Brugnatelli invented this method in 1805 and became the first person to plate a thin layer of gold onto a base of silver. Gold coating is generally used for costume jewellery or to imitate more expensive pieces. It's incredible how almost impossible it is to tell apart the expensive pieces of gold jewellery from the gold plated ones.
Gold coating/plating can be done on most metals, such as nickel, brass, silver, copper and even stainless steel. Nowadays, modern industrial metals like tungsten and titanium are also gold plated often. But out of the above, silver and copper are the most commonly used ones. The unit used for measuring gold coating thickness is called a micron, or 0.001 of a millimetre. Gold coating in thickness can range between .17 to 2.5 microns, the ideal thickness being around .5 to 1.0 microns. While this may sound like a thin layer, it's sufficient enough even for jewellery pieces that are exposed to daily wear, such as rings and bracelets.
You may come across many types of gold coating options while buying gold jewellery. Let take a quick look at the different types of gold platings available and what they actually mean.
GOLD PLATED (GOLD ELECTROPLATED)
Gold plated jewellery means that it has a very light layer of gold (0.05% of actual gold or less) on top of a base metal. The base metal is usually copper, brass, nickel, aluminium, or even a mixture of various metals. Gold plating is also known as gold electroplating as the coating is done via an electroplating solution that gives the jewellery a gold-like appearance.
For a piece of jewellery to be named as "gold plated", the gold layer needs to be between 0.175 microns and 2.5 microns thick and of at least 10k gold quality. Less than 0.175 microns thick are referred to as flash plated or gilt, which is very thin and often badly wearing gold plated finishes. The jewellery which is gold plated must have a stamp indicating plated quality - such as "GP", "GP", "GEP", or "GEP".
- The price is lower than other finishes as the amount of gold is very less
- It can wear off over time since the gold layer is quite thin
- It may tarnish when exposed to any chemicals
- Tarnished gold plated jewellery can often be repaired by having it plated again
- When used as daily-wear, may irritate sensitive skin or may cause skin allergies
Gold vermeil (pronounced as 'ver-may') means heavy gold plating over sterling silver. For this kind of gold coating, the layer needs to be at least 2.5 microns thick, and the minimum gold purity used should be 10 karats. Vermeil coating is a better choice compared to gold plated jewellery items as it has a thicker layer of gold and uses sterling silver as its base metal. Since it's of good quality at a more affordable price, vermeil is one of the favoured choices to be used in jewellery designs as an alternative to solid gold, along with the gold filled finish.
The gold layer of this type of coating lasts a bit longer than gold plated ones and does not rub off quickly, as the gold plating is much thicker here. However, eventually, some gold may wear off if not taken proper care. Gold vermeil coating on a jewellery piece is usually not marked, but when marked with a "925" stamp, it probably means the piece is gold vermeil.
- It does not tarnish quickly and is apt for everyday wearing
- It is also hypoallergenic, so people with metal allergies can wear it safely
- The layer of gold can discolour over time. Routine care and cleaning of the jewellery helps to preserve the plating.
Unlike gold plated and gold vermeil finish, gold filled jewellery is not merely covered with a thin layer of gold, nor is it actually filled with gold. Gold filled metal is created by applying a thick sheet or layer of gold over a base metal core, which is then rolled under heat and high pressure until permanently bonded to the base metal. The base metal used is often brass or copper. The gold purity must be of at least 10K gold, and 12K, 14K or 18K gold can also be used in this process.
To be called as 'gold filled', the gold content must be not less than 1/20 or 5% of the total metal weight, which is why it is often referred to as 1/20 gold. This coating is up to 10 times thicker than the usual gold plated finish. Gold filled jewellery is safe for people with sensitive skin. The gold filled metal must have a stamp that indicates filled/plated quality - such as "GF" or "GF". For example: "1/20 10K GF".
- It is an affordable choice over solid gold with high quality
- The gold layer does not flake or peel off with everyday use
- It is also hypoallergenic as well as safe for all skin types
- With proper care can last for years without losing its gold finish
Another popular type of coating is gold leaf finish. Gold leaf finish is gold that has been flattened into extremely thin sheets and then wrapped (or glided) around a metal base. Gold leaf jewellery is not perfectly smooth and therefore can be recognized by its irregularities at the foil surface surrounding the base metal. This type of finish is often used to decorate artwork and jewellery where 22K or 24K gold is used as the thin gold layers. To find out what kind of gold coating the jewellery has, you need to look for the quality stamp on the item.
WHAT'S THE BEST ONE FOR ME?
The best type of gold jewellery coating that's suited for you depends on a variety of factors - your budget or affordability, how often do you wear it, how regularly you can take good care of it, and many more. Most people usually love gold vermeil and gold filled due to the reason that they're both affordable, yet of high quality and enough for daily wear. However, as the solid gold is the most valuable and long-lasting one, without any worries of allergies or tarnishing over time, it is still favoured over gold plated ones by many for their daily-wear jewellery.