Alloys
Alloys have the function of hardening ductile metals.
In an alloy, the majority metallic element, that is to say constituting the most important part of the mixture, is called "base metal".
Elements added intentionally are called "alloying elements" or "addition elements" and unwanted elements are called "impurities."
Pure 24 carat gold is a ductile metal, that is to say, it is quite soft, and cannot be worked pure in jewelry.
Pure gold is mixed with other metals , precious or not: silver, bronze, copper, etc.
Depending on the metal added, gold takes on different colors.
Depending on the alloys, jewelers affix different hallmarks which allow them to be authenticated quickly.
Alloys - photo credit - fonteacireperdue.com-matières
Gold alloys
Since 1994, only jewelry of 18 carats and above has the right to bear the name “gold”.
This means that they are made with an alloy of 750g of gold per 1000g of metal.
We then say that their title is 750/1000 .
Jewelry made with 9 carat or 14 carat gold is entitled to the name "gold alloy."
Composition of gold alloys
For 750/000 gold jewelry , the remaining 250 g of additional metals give the gold a particular shade.
- yellow gold comprising 125‰ of silver and 125‰ of copper;
rose gold comprising 90‰ silver and 160‰ copper;
- gray gold (or white gold) containing, among other things, 250‰ of nickel or 250‰ of palladium;
- red gold comprising 250 ‰ of copper.
- blue gold containing 250‰ of iron or cobalt;
- green gold comprising 250‰ of silver (the “recipes” may vary)
- purple gold contains 250‰ of aluminum
Add Gold Color Photo Palette
In France, jewelers and jewelers prefer to work with 18K gold.
While a 9K or 14K gold piece of jewelry is harder than an 18K gold piece of jewelry, it is also less durable.
Pieces made with a gold alloy oxidize more easily, react more quickly to perspiration and chemicals, and are more fragile in the event of impact.
To recognize the title of a gold jewel , you just have to check its hallmark .
On the other hand, a gold-plated jewel 9K or 14K are cheaper to buy because of their composition. They will also resell for less.
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In some cases, the color is not obtained by an alloy of metals, but by depositing a plating on it. gives a color superficial on the surface.
Rose gold: Alloy composed of pure gold, silver, and copper.
Grey gold : Alloy composed of pure gold, copper, nickel and zinc.
Green gold : Alloy composed of pure gold, silver.
Blue gold : Alloy composed of pure gold, iron and cobalt.
Purple gold : Alloy composed of pure gold and aluminum.