The number and use of sustainability certification schemes (schemes1) are rapidly increasing, but doubt still persists about their real contributions. This research report aims to explore the impacts of sustainability certification schemes on the ground by undertaking two exploratory case studies based on qualitative information. The aim of the case studies is not to undertake a comparative analysis of the performance of the case studies but to identify impacts of two selected certification schemes, considering participants' points of view. Also, analysis is conducted to assess whether different design characteristics of schemes lead to better outcomes. This report represents the third stage of an applied research project looking into the effectiveness of sustainability certification schemes and standards in the minerals industry and the potential role these initiatives can play to improve standards for responsible mining. Impact evaluation studies on sustainability certification schemes are important instruments not only to add to the growing body of knowledge on the impacts of such schemes, but to address current questions about the effectiveness of such initiatives in delivering positive outcomes. Although there is a consensus among different stakeholders, including standard-setting bodies, governments and civil society representatives, about the importance and need of impact evaluation studies on sustainability standard systems, at the moment substantial knowledge and evidence gaps still persist, especially in the mineral and mining sectors. This report aims to fill these gaps by exploring participants' perceptions regarding the impacts of two selected sustainability certification schemes in mining - the International Cyanide Management Code (ICMC) and the Responsible Jewellery Council (RJC). The analysis presented in this report is based only on information obtained from a qualitative research approach and provided by participants interviewed during the two case studies.