Ever wondered — if the same ring or necklace is made in 18K gold instead of 22K gold, same size, same design — why would the weight be different? The answer lies in a beautiful piece of science. Let's break it down in the simplest way possible.

First: What Is Gold Purity?

Gold purity is measured in Karats (K). Pure gold is 24K. But pure gold is very soft — it's hard to make jewellery with it. So other metals like silver, copper, or zinc are mixed in to make it stronger and more durable.

The Science Behind It: Density

The answer lies in one simple concept: Density — how much mass is packed into a given volume. Different metals have very different densities:

• Pure Gold (24K): ~19.3 g/cm³
• Silver: ~10.5 g/cm³
• Copper: ~8.9 g/cm³

When gold is mixed with silver or copper (like in 18K, which has 25% other metals), the overall density of the alloy decreases. Less dense = lighter weight for the same volume.

A Real-World Example 🪙

Imagine a ring with a volume of 1 cm³ — same design, same size, made in three different purities:

Same ring. Same size. But the 24K version is noticeably heavier than the 18K — simply because pure gold is denser than the metals mixed into lower-karat alloys.

So Which Purity Should You Choose?

There's no single right answer — it depends on how you'll wear it and what matters most to you.

Because understanding your jewellery is the first step to truly loving it. Have questions? We're always here to help. 💛