Statistics on the level and the evolution of stocks of natural assets play a key role in sustainability analyses of economic growth. This paper can be seen as a set of technical guidelines to support the compilation of mineral and energy resource accounts according to the System of Environmental-Economic Accounting (SEEA) 2012. The first part of this paper explains how the coexisting classifications of mineral and energy resources relate to each other and to the classification advocated by the SEEA 2012. It also describes the OECD database on stocks and flows of mineral and energy resources in physical units. Monetary values can be used to compare stocks and flows of heterogeneous assets, and also to characterise the economic benefits of these assets, two tasks that cannot be completed by using physical data only. The valuation of mineral and energy resource stocks poses specific challenges, which are described in the second part of this paper.