18K or 14K: Why Your Engagement Ring Is Never Made of 24K Gold

Brilliant, rare, and resilient, gold has long been a universal symbol of beauty, power, and legacy. This precious metal lies at the heart of fine jewelry, whether for everyday wear, wedding bands, or engagement rings. Yet behind its timeless shine lie many cultural variations: not all gold is created equal. Its composition, measured in karats, varies widely from one country to another. These karat values reflect local traditions, as well as alloy choices that influence the color, durability, and meaning of a piece. True to its values, AGUAdeORO works exclusively with Fairtrade gold, a precious material sourced ethically, with full respect for mining communities and the environment.

The Karat: A Universal Measure

The term “karat” (not to be confused with the carat used for gemstones) refers to the proportion of pure gold contained in an alloy. This unit of measurement is based on a scale of 24 parts. Thus:

• 24 karats: 99.9% pure gold

• 22 karats: 91.6% gold

• 18 karats: 75% gold

• 14 karats: 58.5% gold

• 9 or 10 karats: between 37.5% and 41.7% gold

Alloys: Why Add Other Metals?

The purer the gold, the softer it is. While 24-karat gold dazzles with its deep yellow-orange hue and rarity, its extreme malleability makes it unsuitable for everyday wear. This is why high jewelry typically favors 18-karat gold, a delicate balance between the nobility of gold and the strength required for lasting jewelry.
18-karat gold is composed of 75% pure gold, mixed with metals such as silver, copper, zinc, or palladium. These alloys not only enhance the durability of a piece, but also affect its color: radiant yellow, bright white, or warm rose.
Each karat level reflects specific cultural traditions, sensibilities, and customs, offering designers a rich palette of shades and textures with which to create truly unique pieces.

Why Is Gold Purity Measured in 24 Karats?

The unit used to define the purity of gold, the carat, has its origins in traditions dating back thousands of years. But why is the purity of gold measured on a 24-carat scale?

The choice of the number 24, the basis of the gold carat, dates back to antiquity. In Mesopotamian, Indian and Egyptian civilizations, trade followed non-decimal numerical systems, often duodecimal (base 12) or sexagesimal (base 60). The number 24, a multiple of 12, came to the fore for its ability to be fluidly divided by 2, 3, 4, 6, 8 or 12. This enabled goldsmiths and merchants to precisely fraction gold alloys, long before the invention of the calculator.

So, when an engagement ring is made of 18-carat gold, this means it contains 75% pure gold (18/24), the rest being an alloy of metals such as copper, zinc or silver. This type of gold alloy reinforces the jewel's resistance while subtly modifying its color: yellow gold, pink gold or white gold. Pure gold, or 24-carat gold, although exceptional for its yellow-orange hue, is too malleable for everyday use.

The 24-carat system has also endured thanks to its link with ancient weight systems, such as the troy ounce (used for precious metals), divided into 480 grains, another easily fractionable measure.

Today, this tradition lives on in contemporary jewelry. At AGUAdeORO, every piece of jewelry, from wedding rings to engagement rings, is crafted from Fairtrade-certified 18-carat gold, ethically extracted with respect for man and nature. Caratage thus becomes much more than an indication of purity: it is the reflection of ancestral know-how, combined with a responsible and sustainable commitment. 

Gold around the world

Carat preferences vary around the globe, influenced by history, tradition and everyday usage.

18-carat gold: the perfect balance for European fine jewelry

 An essential reference in luxury jewelry, 18-carat gold is composed of 75% pure gold, combined with other precious metals to reinforce its strength. This karatage is widely used in Europe for the creation of high-end jewelry, notably engagement rings, wedding bands and exceptional jewelry. Its well-balanced brilliance, strength and long-lasting durability make it a highly prized alloy for jewelry houses that combine aesthetics with durability.

22 and 24 carat gold: the prestige of oriental and ceremonial traditions

In Asian and Middle Eastern cultures, exceptionally pure 22 or 24-carat gold is favored for its deep yellow hue and sacred symbolism. This almost pure gold is often reserved for wedding ornaments, ceremonial necklaces and heritage bracelets. In India, China and the Gulf States, a gift of 24-carat gold for a wedding or birth is a highly symbolic gesture, guaranteeing prosperity and cultural roots. Although this type of gold is more malleable, it remains one of the most sought-after for wedding jewelry with traditional and heritage values.

14-carat and 10-carat gold: durable, affordable everyday jewelry

Less noble but very common in Anglo-Saxon countries such as the USA and Canada, 14-carat gold (58.5% pure gold) and 10-carat gold (41.7%) are attractive for their solidity and more affordable price. These alloys are often chosen for jewelry worn on a daily basis: rings, necklaces or earrings. Their resistance to wear makes them practical allies for an active lifestyle. Although less common in fine jewelry, these caratages offer an interesting alternative for those looking for long-lasting jewelry without compromising on design.

Jhumkas in 22-carat gold, a must-have for weddings and major celebrations in certain Indian cultures. (Photo by v.govindaraj raj on Unsplash)

The hallmark: the signature of gold

In European countries, and particularly in Switzerland, hallmarking is a legal and aesthetic guarantee. It authenticates the precious metal, its gold content and its origin. Two hallmarks are generally visible on a piece of jewelry:

- The title hallmark, indicating the gold content.


- The master or brand hallmark, specific to the workshop or company.


At AGUAdeORO, each creation proudly bears the 750 hallmark, guaranteeing its composition in 18-carat gold, as well as our exclusive AGUAdeORO hallmark, proof of authenticity, ethics and Swiss craftsmanship.

Fairy-Tale Blossom ring in 18K yellow gold with AGUAdeORO and Fairtrade pearls. At its center, a brilliant-cut pink cultured sapphire and its halo of cultured diamonds.

Curiosities about Gold

1. Ancient Egypt: the beginnings of the gold standard
As early as 2600 BC, the Egyptians excelled in the art of goldsmithing. They called gold nub, giving its name to Nubia, the gold-bearing region par excellence. Pharaohs were buried with 24-carat gold amulets, supposed to ensure their eternity.

2. India, birthplace of the 24-carat system
The division of pure gold into 24 parts has its origins in ancient India. Sanskrit texts already mentioned this way of assessing purity. This ingenious system spread westwards via trade routes.

3. Rome and the aureus: the imperial gold coin
Under Julius Caesar, the Roman Empire minted the aureus, a pure gold coin weighing almost 8 grams. A symbol of power and stability, it left a lasting mark on European monetary history.

4. Medieval alchemists and the quest for perfect gold
In the Middle Ages, alchemists sought to transform ordinary metals into 24-carat gold using the legendary Philosopher's Stone. A fruitless quest, but one that led to numerous advances in chemistry.

5. Seeds for weighing gold: the botanical origin of the carat
In ancient markets, carob seeds (Ceratonia siliqua) were renowned for their constant weight. They were used as a reference for weighing gold, giving rise to the term carat.

6. Gold, the divine metal of ancient civilizations
Among the Incas, Aztecs and Mesopotamians, gold was not just a precious metal: it symbolized the divine. Nicknamed “the sweat of the sun”, it embodied celestial power and proximity to the gods.

7. Napoleon's engagement ring: the power of a symbol
Napoleon gave Josephine a simple gold ring, with no precious stones. Today, this sober jewel is worth more for its historical significance than for its carat weight.

8. Gold rushes: when the world rushed to riches
Gold fever shaped entire nations: from California (1848) to Australia (1851), the lure of this precious metal turned the economy, migration and history of mankind upside down.

Founded in 2009, AGUAdeORO is a jewelry store with locations in Geneva and Zurich, offering customers the opportunity to purchase ethical jewelry made in Switzerland. Our aim is to offer jewelry that combines sustainable development and elegance.