Sustainability initiatives are a means for the extractive industries to demonstrate that they are operating responsibly and for civil society actors to hold industries and governments to account. In this context, mining sustainability initiatives are increasingly being used. However, with the proliferation of different initiatives in recent years, could they work together better to avoid duplication and deliver combined positive outcomes? This book chapter explores the interoperability of mineral certification schemes through a case study of collaboration by two initiatives: the Responsible Jewellery Council (RJC) and the Alliance for Responsible Mining (ARM). The case study provides important insights from the ground on the main challenges, interactions and improvement opportunities to advance interoperability among different initiatives.