What are the differences between yellow gold, gray gold, pink gold, and white gold?

In the collective unconscious, gold is usually associated with the color yellow, isn't it?
And yet, we find gray, pink, white gold, and even other colors.
Do you know what sets these types of gold apart?

First, let's take a step back to understand where gold comes from.

Yes, if we want to go back to the origins, we first need to look up to the sky and go back some 3.8 billion years.

Recent studies have shown that the Earth was likely hit by a continuous rain of meteorites and comets from various asteroid belts in our solar system, disturbed by the movements of large planets like Jupiter or Neptune. According to researchers, this bombardment lasted at least 100 million years (some even suggest a longer duration, up to 2 billion years), showering the Earth and the Moon with millions of impacts of varying significance. Year after year, all these rocky debris crashed onto our young planet, enriching it with all the metal they were made of, including gold.

Yes, gold does not form peacefully on Earth like diamonds, for example.

No, gold requires the occurrence of an event as unique as it is grandiose: the death of a star.

Imagine a massive star, ten times, a hundred times, a thousand times more massive than our sun, reaching the end of its life. For billions of years, it consumed all the elements it could: hydrogen and helium first, then heavier elements as lighter ones fused together. But now, it has nothing left to burn, and it becomes unstable. Suddenly, under the immense pressure of all these collapsing elements on its core, it explodes, like a regular star would but on an incomparable, titanic scale. It becomes a supernova and offers a cosmic spectacle so bright that it can temporarily eclipse an entire galaxy. It is in this cataclysmic explosion, where the energy is so intense, that the heaviest chemical elements are formed. And notably, this nearly indestructible yellow metal that humanity has not only turned into currency but also into one of the most precious possessions: gold.

Now you understand why gold reserves on our Earth are limited.

Pure gold or alloy?

When extracted, gold is naturally yellow, and we call it pure gold, unalloyed, the famous 24-carat gold. But as incredible as it may seem, pure gold is easily malleable, and in reality, unless it is massive, a fine piece of pure gold jewelry tends to deform. That's why gold marketed in jewelry is generally an alloy of several metals to ensure the rigidity of the whole.

Gold shows us all the colors!

As you may have understood, it is through the various alloys that we obtain several shades of gold. In the world of jewelry, we mainly find yellow gold, pink gold, gray gold, and white gold. Here are their differences in terms of composition:

• Yellow gold: 75% gold, 12.5% silver, and 12.5% copper
• Pink gold: 75% gold, 20% copper, and 5% silver
• Gray gold: 75% gold, approximately 15% silver, and sometimes palladium
• White gold: It is generally used to refer to gray gold.
  Before it was regulated, nickel was part of its composition; now, white gold is coated with a thin layer of rhodium. However, as this tends to fade over time, you should consider reapplying it at a jeweler to maintain the color.

These alloys are composed of different metals (silver, copper, etc.), with the main base always being pure gold (yellow).

Know that there are other possible colors, less common but that you might come across: green gold, blue gold, and even violet gold (an alloy of gold and aluminum).

9, 18, or 24 carats?

Applied to precious metals, the carat corresponds to their purity index.

Pure gold is 24-carat gold, but as explained earlier, it is too soft to be worked in jewelry.

18-carat gold is the perfect balance between the amount of pure gold (75%) and other metals. It allows for work while retaining its non-corrosive and non-allergenic qualities. Due to the high amount of gold, the jewelry has a more vibrant color and ages well over time, ideal for daily wear.

As for 9-carat gold, it is harder than 18-carat gold because there is less gold, so more poor metals. But, in fact, it is also more brittle. Containing more copper and silver, it will oxidize more easily and be less shiny. Finally, if 9-carat gold contains half the gold of 18k gold (37.5% instead of the minimum 75%), you will find few sellers who will sell it at half the price...

So, whether gray gold, white gold, yellow gold, or even pink, it's a matter of taste...

However, it is crucial to pay attention to the number of carats in your jewelry.