Platinum vs white gold: which metal suits a lab-grown diamond ring?

White gold and platinum are the two standard metal choices for lab-grown diamond rings, and each behaves differently in wear, colour stability, and cost. White gold is an alloy of 75% pure gold (18K) mixed with palladium, then rhodium-plated to a bright white finish; platinum is a naturally white metal, typically 95% pure (stamped .950), and roughly 34% denser than gold by volume. The key practical difference is colour retention: platinum keeps its white-grey tone permanently, while white gold gradually shows warmer undertones at contact points as rhodium wears, requiring replating every few years. For lab-grown diamond settings specifically, harder white gold alloys grip small pavé prongs more securely, making them a sound choice for halo or pavé designs; platinum suits engraved bands and heavier statement settings where long-term volume and patina matter more than surface hardness. Platinum rings carry a higher price due to greater raw material density and higher purity content, so the metal choice affects total ring cost independently of the lab-grown diamond grade.