Types of Gold

Karat is how gold purity is measured, out of 24. 24k is pure gold. 18k is 75 per cent pure gold (stamped 750). 14k is 58.3 per cent pure gold (stamped 585). 9ct is 37.5 per cent pure gold (stamped 375), common in Australia and the UK. 10k is 41.7 per cent (stamped 417), common in the US. Karat and carat are the same measurement; "karat" is the spelling typically used for gold, "carat" for diamond weight, though Australia uses both spellings for gold.

Gold comes in three main colours, set by the alloy mixed with the pure gold. Yellow gold is the natural warm colour of gold, kept warm by alloying with silver and copper. White gold starts out a faint grey-yellow and is plated with rhodium for the bright white finish. Rose gold gets its pink from copper, and the more copper in the alloy, the deeper the pink. Higher karats show their colour more strongly; lower karats look paler.

24k is too soft for everyday jewellery. 22k is the traditional choice for Indian and Middle Eastern gold but is still soft for rings worn through busy days. 18k is the fine-jewellery standard across most of Europe and the higher end of the Australian market. 14k is the most popular karat for engagement rings in Australia and the US because of the harder, more practical balance of gold content and durability. 9ct is the most affordable karat with the highest hardness and the palest colour.

Choose 14k for daily-wear engagement rings, wedding bands and most fine jewellery. Choose 18k for richer colour and a more luxurious feel, particularly in yellow and rose gold. Choose 9ct for budget-friendly fine jewellery that needs to be hard. Mixed-metal designs (yellow gold band with white gold prongs, or rose gold band with a platinum head) let you combine colours where they make sense. Cultural jewellery often uses 22k or 24k regardless of the durability trade-off.

All solid gold cleans up with warm soapy water and a soft brush. Avoid chlorine, harsh chemicals and storage next to harder stones. White gold needs occasional rhodium re-plating; yellow and rose gold do not. Higher karats scratch more easily, so a yearly polish on an 18k piece is normal if you want the bright finish back.

Gold price tracks the global gold market in AUD and rises and falls accordingly. Within a single design, 18k costs more than 14k because of the higher gold content; 9ct is the most affordable. Across colours at the same karat, yellow, white and rose gold are similar in price; rose can sit slightly lower because copper is cheaper than palladium. Recycled gold costs the same as newly mined gold and has identical properties.