Mineral Metal-Oxalates Formed by Hydrogen Bonds: The New Potential Two-Dimensional Natural Crystalline Structures

Crystalline structures with a thickness of less than 100 nm are paradigm materials to support the new technologies foreseen for the next decades. Research into these new materials began with crystals with a structure formed by van der Waals forces, such as graphene. Crystalline structures formed by hydrogen bonds stand out for similar potential: the Metal-Organic Framework (MOF). Despite its outstanding properties, its popularization has not yet been possible and a cliché solution to make this nanomaterial widely available is to exploit it from mineral reserves. Two-dimensional natural substances are not yet economically exploited directly from mineral reserves, but their potential has been proving prominent in the abundant availability of raw materials for the nanotechnology industry. Stepanovite and zhemchuzhnikovite are two mineral species that are highlighted for presenting these structures and having a natural origin. This review work presents the evolution of knowledge about two-dimensional materials, the context in which research on MOF minerals arises, and the potential application of these substances in the high-tech industry. Due to the delicate context of mineralogical genesis, stepanovite and zhemchuzhnikovite are rare minerals and it would be presumptuous to consider a sufficient abundance of these substances to be viable for mining extraction. The most emerging alternative seems to be the geomimetic synthesis processes of these substances in a controlled environment, inspired by the natural crystallization process.