Platinum vs White Gold: the differences
Comparison of density, wear and price between these two white metals.
Confusion between platinum and white gold is frequent — both are shiny white, but their compositions and values are radically different. White gold is not platinum.
18k White Gold: Gold alloy (750‰), palladium or nickel (to whiten), rhodium (surface layer by electrodeposition). Density: 15–16 g/cm³. Metal cost for 8g: CHF ~495 (75% gold, 25% white alloys).
950 Platinum: Pure metal (950‰), iridium/ruthenium alloys. Density: 21.4 g/cm³. Metal cost for 8g: CHF ~237. Yes — platinum is cheaper in metal cost than 18k white gold, but craftsmanship is longer and more complex, which primes over the final cost.
How to Distinguish Them: Hallmark: '750' or '18K' = white gold. '950 PT' = platinum. Densimetric test: 8g of white gold occupies ~0.5cm³; 8g of platinum ~0.37cm³ (denser). To be weighed and measured. Acid test: white gold resists standard acids; aqua regia dissolves both.
Maintenance: White gold requires re-rhodiuming every 2–3 years (as the rhodium layer wears, the slightly yellowish alloy reappears). Platinum requires no surface treatment — it ages in an intrinsic and elegant way.