Meaning of 24 karat gold purity
Gold is the only naturally yellow metal. Even when it is not pure, it is difficult to change its color. Known to mankind for more than 6,000 years, it has been the foundation of all global economies since ancient times.
Pure gold is yellow, shiny, and unalterable. It has fascinated humanity since its discovery, and today, 24-karat gold is still used not only in jewelry but also by investors and as a guarantee for banks worldwide.
Of the three precious metals used in jewelry, gold is the most common and the most coveted. Even though platinum's price exceeds that of gold, everyone knows gold and knows they can buy or sell it easily anywhere in the world.
24k gold wedding ring with the hallmark 24k
INDEX
- What is pure gold?
- Gold karatage
- Price of 24-karat gold
- How is pure gold obtained?
- Advantages and disadvantages of pure gold for jewelry
- Pure gold rings and chains
- The future of 24k gold jewelry
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1. What is pure gold ?
Pure gold contains at least 99.9% gold by weight. Pure gold is also known as fine gold, meaning it has no other metals mixed in.
This type of gold is also referred to as:
- Gold 999
- 24-karat gold
There are industrial processes to obtain gold that is purer than 99.9%, as we will see later.
Characteristics of Fine Gold
Before being a precious metal, gold has many unique properties that distinguish it from other metals:
- It is naturally found in its pure yellow form (though not pure gold) as nuggets or associated with other metals.
- It is a very dense metal with a density of 19.5 when the gold is pure, which allows it to be easily separated from other lighter elements.
- It is the most malleable of all metals, making it easy to work with by hand or with machines to shape it.
- It is very ductile, meaning that one ounce of gold (31.10 grams) can be stretched into a wire over two kilometers long. For this reason, it was used to mint coins.
- It is unalterable, meaning that bases and acids do not attack it. This makes gold very durable when exposed to air and even chemicals.
- It melts easily, with a melting point of 1064°C (1947°F)
- Its electrical and thermal conductivity properties make it useful in the electronics industry.
- It shines brightly once polished, which explains its use in jewelry.
- It is rare, with an average concentration in the Earth's crust of 0.004 grams per ton of rock.
- Gold only dissolves in aqua regia, which is a mixture of nitric acid and hydrochloric acid.
This picture shows pure gold nuggets at the center, pure platinum on the left and pure silver on the right
Where Does Gold Come From?
Although gold is extracted from underground, it was not formed on Earth, unlike diamonds and other gemstones that are produced through complex chemical processes occurring deep within the Earth.
Gold was formed in space through stellar nucleosynthesis. The current state of science suggests that during the explosion of a star in a supernova, the iron core of the star is subjected to a large enough flow of neutrons to transmute the iron atoms into heavier atoms, including gold, platinum, and silver.
Remember that the atomic number of gold is 79, while that of iron is 26.
The gold thus formed dispersed into space and mixed with the protoplanetary gas cloud that later formed our solar system and Earth. Therefore, gold is present everywhere on Earth, but its density and tendency to bond with iron cause terrestrial gold to concentrate mainly in the core of our planet.
Yes, the gold of the Earth is not on the surface but in its center.
Geochemical and magmatic activity in the Earth's crust allows buried gold to reach the surface to be found or exploited.
Today, gold is extracted from open-pit mines. Rocks are extracted and processed industrially to extract metals, including gold, through various complex chemical processes.
It is estimated that a concentration of at least one gram of gold per ton of rock is required for the industrial extraction of gold from a mining site to be profitable.
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2. Gold karatage
As explained previously, fine gold is pure gold.
Do You Know What a Karat Is?
The etymological origin of the jeweler's karat comes from the word "Quirat," an ancient maritime term that expresses the ownership share of a ship when it belongs to multiple people.
The ship is subdivided into 24 equal-value parts ("one quirat"), and each owner holds a certain number of "quirats," representing the percentage of the ship's shares that each investor possesses.
Thus, the karat of gold expresses how many of the 24 parts of the metal are pure gold.
Caution, karat is not carat
The carat of a gemstone (ct) expresses a weight of 0.2 grams. This is different from the gold karat, which expresses a proportion (percentage).
Why Mix Gold with Other Metals?
As with all alloys, the goal is to improve the properties of the base metal.
Gold is a noble metal with many advantageous properties, but in its pure state, it does not resist impacts and scratches well.
Consequently, a piece of pure gold jewelry (24 karats) that is thin would easily deform with a small impact. Therefore, when we manufacture 24-karat gold jewelry, we tend to give it a solid design to compensate for the metal's malleability and to withstand impacts.
Gold Karatage
To enhance the natural qualities of gold, it is mixed with other metals. The most common gold alloys are as follows:
- 18k: 18-karat gold (75% of its weight in pure gold) is the most precious of the solid gold alloys used in conventional jewelry.
- 14k: 14-karat gold (58.4% of its weight in pure gold) is the most common because it is much more affordable than 18-karat gold and retains a color very close to it.
- 9k: 9-karat gold (37.5% of its weight in pure gold) is the most affordable gold alloy on the jewelry market, with more than half of its weight being non-gold.
There are more gold karatages, and this chart shows the correspondence between karatage and the percentage of fine gold in the metal.
This table shows the relation between the karatage of gold and the percentage of purity of gold
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3. Price of 24-karat gold
The price of precious metal is always expressed as pure, 24-karat gold, and it varies every day. This chart shows the trend in the price of pure gold since the 1900s.
Gold price trend during the last 130 years
As we can see, in the long term, gold does not lose value. Pure gold is not an asset and is not considered as profitable to hold compared to assets like businesses. However, during times of economic crisis, 24k gold remains the best economic guarantee.
4. How is pure gold obtained?
24-Karat Gold is 100% Pure Gold, in Theory.
Currently, 100% pure gold does not exist. Depending on natural deposits, it is possible to find native gold that is pure up to 22 or even 23 karats.
Various chemical processes have been discovered to refine and concentrate gold. The most common is the Miller process, which produces gold with a purity of 99.95%. This is the standard pure gold used to make gold bars. This type of pure gold is called 3-9 gold (999).
The purest gold that can currently be produced is obtained through the Wohlwill process, which allows for 99.999% pure gold. Few refining sites are capable of implementing such a treatment process. The Royal Canadian Mint is known for using this gold refining process for the production of pure gold bars and coins. This type of pure gold is called 5-9 gold.
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5. Advantages and disadvantages of pure gold for jewelry
Pure gold has an incomparable yellow color, and its density gives significant weight to jewelry. This is why it is common for certain men to want their jewelry made from pure gold.
While the advantages of fine gold are obvious in terms of aesthetics, there are disadvantages to 24-karat gold for jewelry:
- Being so malleable, the jewelry needs to be thick to be more resistant.
- Given the metal's high density, such jewelry is heavy and expensive due to the metal's cost.
- Polishing 24k gold is difficult for the jeweler, and the metal is easily scratched, losing its shine.
- Fine gold is not suitable for setting stones with prongs, which limits the designs that can be made with it.
Considering these points, certain jewelry designs are suitable for being made of 24-karat gold if you have the budget for this type of jewelry.
6. Pure gold rings and chains
With the right design, many pieces of jewelry can be made from fine gold, as shown by these examples of rings, wedding bands, earrings, pendants...
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7. The future of 24k gold jewelry
While pure gold jewelry is rare in the West, it is very common in Asia. For centuries, the Chinese, in particular, have been fond of 24-karat gold jewelry because it offers an incomparable color, serves as a social status symbol, and can be sold anywhere in the world at any time if needed.
For this reason, there are jewelry manufacturers in Asia specializing in the production of pure gold jewelry who have developed modern techniques to create lightweight and durable pure gold jewelry.
This process is known as 24k hard gold electroforming and involves depositing thick layers of gold onto a wax mold using currents controlled by computers. This process is very similar to the gold electrolysis process used to create gold plating, but it produces thicker gold layers ranging from 0.1 to 0.3 millimeters in thickness.
Here are the main advantages of this type of gold electroforming process:
- Jewelry can be made with 24k gold.
- Fine, complex, and hollow shapes can be created.
- Large, very lightweight pieces can be manufactured.
- It allows for the industrial production of many pieces in total, reducing production costs.
- No waste or loss of metal is generated with this process.
With this new, more eco-friendly process that offers better control of gold deposit purity, combined with advantages in terms of wear resistance, the leading producers of 24-karat gold jewelry in the Asian market are eager to expand into the American market.
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