Diamond Jewellery Buying Guide: Certification, the 4Cs & What Changed in 2026
Diamond jewellery runs on an entirely different verification system from the gold hallmark covered elsewhere on our site, and a major regulatory change in January 2026 just made that system stricter and more transparent than it’s ever been. This guide covers what actually matters when buying diamond jewellery: how certification works, what the 4Cs mean,…