Platinum
A naturally white precious metal, denser and rarer than gold. Never needs plating, and does not fade.
Jewellery platinum is usually 95% pure, hallmarked 950, far higher than any gold alloy in common use.
It is genuinely white all the way through, so unlike white gold it never needs rhodium re-plating.
It does not wear away so much as move. Scratches displace metal rather than removing it, building a soft grey patina that many owners prefer.
When you are buying
Platinum is heavier and dearer than gold per piece, and it is hypoallergenic. If you have reacted to white gold before, the nickel in the alloy was the likely cause and platinum solves it.
White Gold
Gold alloyed with white metals and then usually rhodium plated. The white you see is a coating, not the metal.
Rhodium Plating
A thin layer of rhodium over silver or white gold, giving a bright white finish that resists tarnish.
Hypoallergenic
Metal unlikely to cause a skin reaction. In practice it means nickel-free, since nickel causes most jewellery allergies.
Hallmark
An official stamp certifying precious metal purity. In India, BIS hallmarking is mandatory for gold jewellery.