Engagement Ring Materials Guide

Start with how the piece will be worn. An engagement ring worn every day needs a hard stone (diamond, moissanite, sapphire, ruby) and a hard-wearing metal (14k gold or platinum). A pair of earrings can use a softer stone and a softer metal because it sees less impact.

Then think about look. Cool stones in cool metals read clean and modern. Warm stones in warm metals read traditional. Mixed combinations are very common in fine jewellery and rarely look wrong.

Moissanite is lab-grown silicon carbide. It is 9.25 on the Mohs hardness scale, only below diamond at 10. It has a higher refractive index and more fire than diamond, so it sparkles with more rainbow flashes. The look is similar to diamond from a distance, more colourful up close.

Moissanite typically costs 10 to 15 per cent of a diamond at the same size. For more, read the full moissanite guide.

Lab-grown diamond is carbon, exactly like a mined diamond. It is graded on the same 4Cs scale and certified by the same labs (IGI, GIA, GCAL). The only meaningful difference is how it got here. Lab-grown stones are grown in weeks rather than over geological time.

Prices typically run 20 to 40 per cent of a comparable mined diamond, which is why lab-grown has become the default choice for buyers who want diamond at a sensible price. For more, read the lab-grown diamonds guide.

Solid gold comes in different karats. 24k is pure gold, too soft for jewellery. 18k is 75 per cent gold and a popular fine-jewellery standard. 14k is 58.3 per cent gold and the most common karat for engagement rings in Australia. 10k is the hardest and cheapest but has the palest colour.

Gold also comes in colours. Yellow gold is alloyed with silver and copper. Rose gold uses copper for the pink. White gold uses palladium and plating, covered below. Compare karats in the 14k vs 18k gold guide.

White gold is gold alloyed with palladium and silver, then plated with rhodium for the bright white finish. The plating wears over time and needs to be redone every two to three years for a ring worn daily. Compare it with platinum in the platinum vs white gold guide.

Platinum is a naturally white precious metal used at 95 per cent purity. It is denser and rarer than gold, never needs plating and holds stones more securely over time. Platinum settings typically cost 30 to 50 per cent more than white gold. Hypoallergenic for sensitive skin.

Sterling silver is 92.5 per cent pure silver and 7.5 per cent alloy, usually copper. It is bright white and inexpensive, but it is too soft for engagement rings and it tarnishes over time as the copper reacts with air and skin. Best used for earrings, pendants, bracelets and fashion jewellery rather than rings worn daily.

A practical engagement ring brief is: lab-grown diamond or moissanite, set in 14k or 18k gold or platinum, in the metal colour that matches the rest of your jewellery. For a piece worn occasionally, you can stretch into softer stones, 22k gold or sterling silver.

If you are deciding between specific options, the linked comparison guides below go deeper on the trade-offs (14k vs 18k, platinum vs white gold, moissanite vs diamond).