Which Gold is Harder? 9ct or 18ct?
Understanding Gold Hardness
Many people who research wedding rings, whether online or by speaking with shop staff, are told that 9ct gold is harder than 18ct gold. While this is sometimes true, it isn’t the whole story. The carat of gold does affect hardness, but to fully understand this precious metal and choose the right alloy for your needs, it's also essential to consider the colour of the gold. The shade of gold depends on the other metals mixed with pure gold to create 9ct, 14ct, and 18ct alloys. An alloy is simply a combination of two or more metals. Pure gold is 24ct; 18ct gold contains 75% pure gold and 25% other metals (hallmarked 750), 14ct is 58.5% gold and 41.5% other metals (hallmarked 585), and 9ct is 37.5% gold with 62.5% other metals (hallmarked 375).
The Role of Alloying Metals
The specific metals added to gold determine both its colour and hardness. Think of it like mixing paint: to create yellow or rose gold, silver and copper are combined with gold. More copper results in a rosier hue and increased hardness, while more silver creates a whiter tone but also softens the alloy. Copper is harder than silver, so the proportion of these metals in the alloy directly impacts the final properties of the gold.
Comparing Hardness in Different Gold Colours
For yellow gold, 9ct is harder than 18ct because it contains a higher percentage of copper. However, when it comes to white gold, the story changes. White gold alloys contain more silver, which softens the metal. As a result, 9ct white gold, with its greater silver content, is softer than 18ct white gold, which has less silver relative to gold.
Choosing the Best Metal for You
In summary, 9ct yellow gold is harder than 18ct yellow gold due to its higher copper content, while 18ct white gold is harder than 9ct white gold because the latter contains more silver, making it softer. When selecting your ring, it's best to decide first on the colour—white, yellow, or rose—and then consider how important hardness is to you.
All rings I craft are made to be durable and to allow for future alterations without worry. I always consider how the piece will be worn and how often, ensuring that each ring is robust enough to last and adaptable to life's changes. My approach is guided by the principle that if alterations are ever needed, I will be the one performing them, so I ensure every ring is made strong enough to be resized and adjusted as necessary.
