Pure gold is not used to make jewelry. Surprising? Yet it's true: 24-karat gold is so soft that a pure gold ring would bend in your pocket and scratch at the slightest contact. To become a piece you can wear for years, gold must be married to other metals. It is this marriage - the alloy - that creates everything: the durability, the color, and the karat.
Understanding alloys means understanding why 18K gold and 14K gold don't have the same value, why rose gold exists, and why two pieces "in gold" can sell for very different prices.
At Jayma Or, a gold buyer established in Dakar, we evaluate jewelry of every karat and every color every day. We test, we weigh in front of you, and we pay cash, the same day, based on the world rate. Here, in plain terms, is what lies behind the idea of an alloy.
In this article, you will discover:
- why gold is alloyed and what that changes;
- how the alloy sets the karat and the purity percentage;
- where yellow gold, white gold, and rose gold come from;
- what the alloy means for the resale value of your jewelry.
Why gold is alloyed: durability above all
Gold is a noble metal: it does not rust, does not tarnish, and resists time. But it has one major drawback for jewelry: it is extremely soft. In its pure state, it bends, scratches, and loses its shape.
The solution found since antiquity: adding small amounts of other metals - copper, silver, zinc, sometimes palladium or nickel. These metals harden the gold, make it resistant to daily wear, and allow the jeweler to work fine, precise shapes. This controlled mixture is what we call an alloy.
How the alloy creates the karat
The karat is nothing more than the proportion of pure gold in the alloy, measured out of 24. The more other metals are added, the lower the karat. The proportions are precise and standardized:
- 24 karat: 99.9% gold - almost no alloy.
- 21 karat: 87.5% gold, so 12.5% other metals.
- 18 karat: 75% gold, 25% alloy.
- 14 karat: 58.3% gold, the rest in other metals.
This is the key to remember: the karat tells you exactly what share of the piece is really gold. A 14K piece is sturdy and affordable, but it contains only a little more than half gold. To place each type of gold and its uses, see our guide on the different types of gold.
Where yellow, white, and rose come from
Here is one of the most fascinating aspects of the alloy: it doesn't only change the durability, it changes the color. Pure gold is naturally a warm yellow. By changing the metals added, you obtain different shades:
- Yellow gold. A classic alloy of gold, copper, and silver. It keeps the warm, traditional hue of gold - the most prized in West Africa.
- White gold. Gold is alloyed with white metals (palladium, sometimes nickel, silver), often coated with a thin layer of rhodium for a silvery shine. This plating can fade over the years and need to be redone.
- Rose gold. A higher proportion of copper gives this soft, pinkish hue, which is very much in fashion.
An essential point to understand: at equal karat, color changes nothing about the value. An 18K white gold and an 18K yellow gold contain the same amount of gold and are bought back at the same price. Color is a matter of style, not of value.
What the alloy changes for resale
When you resell a piece, it is not "the piece" that is evaluated, but the amount of pure gold it contains. The alloy therefore enters directly into the calculation:
- We identify the karat (via the hallmark or a test), that is, the percentage of gold.
- We weigh the piece to the gram, in front of you.
- We apply the day's rate corresponding to that karat.
The result: two pieces of the same weight but different karats will not have the same value. 21K pays more than 14K, simply because it contains more gold and less alloy. Try it: find the hallmark on your piece, then compare it to the day's rate displayed on our homepage, karat by karat.
Frequently Asked Questions
Why isn't my piece made of pure gold?
Because pure gold (24K) is too soft for a piece worn every day: it bends and scratches. The alloy makes it resistant while keeping the essential of its value.
Does white gold really contain gold?
Yes, as much as yellow gold of the same karat. 18K white gold contains 75% gold; only the color changes, thanks to the alloy metals and the rhodium plating. The buyback value is identical at equal karat.
Is a low-karat piece still worth something?
Absolutely. As long as it is solid gold, even a 14K piece has a real value, calculated by weight. It simply contains less gold per gram than a higher karat.
How do I find out the karat of a piece with no hallmark?
A professional test determines the purity precisely, without damaging the piece. We carry it out in front of you, free of charge, before any estimate.
Take action: know the true composition of your gold
You now understand that everything starts with the alloy: the durability, the color, and above all the karat that determines the value. The only thing left to find out is what your piece contains.
For a free, no-obligation estimate: send a photo by WhatsApp to +221 78 111 66 87, or make an appointment. We test the karat, weigh in front of you, and pay cash the same day - and if you can't come to us, we send a trusted courier to you.