Gold Purity: Difference between carats, karats and 9k, 14k, 18k, 24k gold?

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Gold Purity: Difference between carats, karats and 9k, 14k, 18k, 24k gold?

We often see gold expressed in karats (k, kt) or carats (ct). What does this mean?

Firstly, depending on where you are from, the terms ‘karat’ or ‘carat’ can have different meanings. Generally in the US and Canada, ‘karat’ is used to denote the purity of gold, whereas ‘carat’ is used to express the weight of precious stones and pearls. In the UK and Australia, ‘carat’ is the spelling more commonly used to refer to purity of gold OR the weight of precious stones.

What does carat or karat mean for gold?

100% pure gold is expressed as 24 carats. Pure gold is actually a very soft substance, so in order for us to use gold practically in applications like jewellery, gold is often mixed with other metals to make it harder and stronger. These mixtures of gold and metals are called ‘gold alloys’.

When we talk about carats, the number of carats in gold is a measurement of how much of the alloy (out of 24 parts) is made of pure gold. I.e. In 9ct gold, 9 parts out of 24 are made of pure gold. The other 15 parts are comprised of a different metal to enhance the strength of the piece. Similarly, 18ct gold is 18 out of 24 parts pure gold, whereas the other 6 parts is comprised of another metal.

You may also find that certain gold jewellery is stamped with a three digit number. This also denotes the purity of the gold. For example, 9ct gold is 9/24 pure gold. Expressed as a percentage 9ct gold is 37.5% pure gold, so you will often find a 9ct gold piece of jewellery stamped as “375”. Similarly 18ct gold will be shown as 750 as it is 75% (or 18/24) pure gold.

Whatever carat you choose, solid gold is and always will be a precious metal and a superior choice for jewellery over anything that is gold plated or gold filled. At SIT & WONDER we believe in providing affordable fine jewellery options so that you can enjoy the benefits of real solid gold and sterling silver jewellery that will last and not fade over time.