STUDY01: What does the "K" in K10 and K18 mean?
The symbols K10 and K18, which are often seen in jewelry shops and magazines, are also primarily handled at cobaco.
"K" is the initial of the unit "karat," which indicates the purity of gold. It represents the proportion of gold contained in jewelry. By the way, the term "carat," which denotes the mass of gemstones such as diamonds, is spelled with a "C." Please note that it is a completely different unit.
The gold content is 75% for "K18", 58% for "K14", and 41.7% for "K10". By the way, "K24" represents pure gold, meaning it is 100% gold. Although it is harder than platinum and silver, it is a very delicate and soft metal, so it is not common to make jewelry from K24 (pure gold) as it is.
If it is soft and has a high risk of deformation, it is not suitable for everyday use. Therefore, materials such as "K18" and "K10" come into play. By alloying gold with other metals, its strength is enhanced.
The type of metal added varies depending on the factory that performs the smelting and refining of the base metal, but generally, silver and copper are commonly mixed. In the case of pink gold, a higher amount of copper is often added to adjust the color tone.
STUDY02: Different colors and strengths,K10 and K18
K10 and K18. It's not that one is better than the other, but each has its own characteristics.
K10 is stronger than K18, making it less prone to deformation and scratches. However, due to its hardness, it is not very resistant to strong impacts, especially...When subjected to pinpoint impacts, it becomes more prone to breaking. Additionally, it is sensitive to acids and can easily discolor if not maintained regularly.
Particularly, pink gold is prone to discoloration due to the influence of the metals it contains, so a bit of caution is necessary. However, compared to "K18," there are many options available at more affordable prices, making it easier for jewelry beginners to incorporate into their collection.
K18 has a high gold content, making it less prone to discoloration, and its shine is different compared to K10. Additionally, it is said to be less likely to cause allergic reactions than K10, so those with allergies may feel more comfortable wearing K18 (※ not everyone will be free from allergic reactions).
K10 is softer, so you need to be careful when handling thin necklace chains, but on the flip side, it means there is toughness. When subjected to impact,K18 is also characterized by being less prone to breaking compared to K10.
By the way, at cobaco, we also offer items made from a material called "K18 Hard," which is harder and less prone to bending than regular K18, centered around rings. It is a material that combines the hardness of K10 with the high toughness that K18 originally possesses. If you are interested,HerePlease take a look at the page as well.
STUDY03：The shade of gold varies by brand
Is the color tone the same for K10 and K18? In fact, compared to K18, K10 has a slightly stronger pink hue in pink gold, and in yellow gold, it has a slightly lighter and softer color tone.
K10/K18 Yellow Gold Color Comparison
K10/K18 Pink Gold Color Comparison
And with K18 hard, even in yellow goldピンクゴールドでも、Compared to regular K18, it will have a lighter color tone.
Left: K18 Hard Yellow Gold Right: K18 Hard Pink Gold
The color variations can change slightly depending on the brand or shop. At cobaco, we also adjust the color combinations to match the design of the jewelry.
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K10とK18。If you take proper care of them, you can wear both for a long time. We hope you will consider your budget, color preferences, compatibility with your existing jewelry, and the occasions you will wear them when making your selection.
