96.5% gold, 18K and platinum — which belongs on which piece

This is the question we field most often, and the honest answer is that none of them is better. They are built for different jobs.

What the numbers mean

Pure gold is far too soft for jewellery, so it is alloyed with other metals for hardness. The number tells you how much gold is in the mix.

What 96.5% gold is really for

The 96.5% standard is specifically Thai. Elsewhere in Asia you will find 99.99% or 91.6% (22K) instead — they are not interchangeable.

Its advantages are a deep yellow colour that 18K simply cannot reach, and more importantly, it can be sold back at the Gold Traders Association rate, the reference price every Thai shop quotes against. That makes Thai gold jewellery a wearable asset as much as an ornament.

The trade-off is softness. It scratches easily and can deform under a hard knock.

Why a diamond ring should not be 96.5%

Because claws holding a stone are under constant load. Gold that soft slowly opens up with daily wear, and one day the stone is gone.

We see this at the bench regularly — rings bought elsewhere, brought in for repair, with 96.5% claws so fatigued the whole head has to be rebuilt.

Anything with a set stone should be 18K or above, or platinum. For pieces that are all about the metal itself — chains, bangles, plain bands — 96.5% is perfectly sound.

Platinum is not white gold

These are constantly confused, and they are not the same material at all.

18K white gold is yellow gold alloyed with white metals, then plated in rhodium for brightness. That plating wears. Worn daily, it needs redoing every one to two years or the warm tone underneath begins to show.

Platinum is white all the way through. Nothing to replate. As it wears it does not lose metal so much as develop a soft matte surface — the patina European buyers often prefer to the new finish.

Platinum is about 60% heavier than gold at the same volume and costs more because more metal goes into the piece. For an engagement ring worn every day for thirty years, it is the better economics.

Always read the hallmark

Properly made jewellery is stamped with its purity. Look inside the shank, on the clasp, or on the back of a pendant.

You should find two things: the purity number (965, 750, 585, Pt950) and the maker's mark. No mark at all is a reason to ask questions — it means nobody can be traced as the maker.