The key difference lies in the alloy used. 18k rose gold contains 75% pure gold blended with copper and occasionally silver, giving it its characteristic rosy tone. White gold, by contrast, is an alloy of pure gold with white metals such as palladium.
Quality rose gold requires no plating, unlike white gold, which is often rhodium-plated. Both metals offer the same durability at 18k, yet rose gold naturally retains its colour over time.
The choice between these two metals comes down to your aesthetic preferences and the style of your engagement ring.