18-karat gold is a popular choice for jewelry, but what is it made of, besides gold? Let’s see how much silver there is in a typical 18K gold piece.
The Meaning of Karat Numbers
Karat is a measure of gold content.
The karat of a gold item is calculated by dividing the mass of pure gold in it by its total mass and multiplying the result by 24.
Thus, a piece that contains 58% gold is approximately 14 karats (0.58 x 24).
What Is the Meaning of 18 Karats?
From the above definition of karat, you can see that 18-karat gold has a purity of 75% (18/24).
Therefore, 25% of 18K gold is made up of other metals.
The most common metals used in gold alloys are copper, silver, zinc, and nickel.
18-Karat Yellow Gold and Silver Content
The yellow gold alloy used in jewelry is usually made by mixing pure gold with copper and silver.
Nickel can also be used, but many jewelry makers avoid it because it can cause skin allergies in some people.
Usually, the silver content in 18K yellow gold can vary between 10% and 13%.
A typical 18-karat yellow gold alloy contains the following metals: 75% gold, 12.5% copper, and 12.5% silver.
Another common 18-karat alloy contains the same metals in the following proportions: 75% gold, 15% copper, and 10% silver.
You should keep in mind that the proportions of non-gold metals in 18K gold are not set in stone and may vary from one producer to another.
However, the silver content of such an alloy is most likely to be in the 10-12% range.
Silver Content in 18K White Gold
White gold is made by covering a yellow gold alloy with rhodium, which makes the piece’s surface look white and shiny.
An 18-karat white gold alloy also contains 75% gold, but the makeup of the rest is slightly different.
18K gold may contain nickel, manganese, or palladium, which make the resulting alloy look whiter than a yellow gold mixture.
Other metals that 18K gold can contain are zinc and platinum.
A common white gold alloy contains 75% gold, 2.5% silver, 8% nickel, 10% copper, and 4.5% zinc.
However, the non-gold metals and their proportions can vary widely, so the above example should not be taken as a benchmark.
For example, silver and platinum can be added in greater proportions to a white gold alloy that will be used in gemstone settings, as these metals increase the durability of the material.
White gold does not necessarily contain silver – it is not uncommon for white gold alloys to be made without this metal.
As you can see, the silver content of an 18K white gold can vary widely – from 0% to more than 5%.
You should therefore not assume that a given 18-karat white gold piece contains a certain amount of silver.