Understanding geology through crystal engineering: coordination complexes, coordination polymers and metal–organic frameworks as minerals

Recent structural studies of organic minerals, coupled with the intense search for new carbon-containing mineral species, have revealed naturally occurring structures analogous to those of advanced materials, such as coordination polymers and even open metal–organic frameworks exhibiting nanometre-sized channels. While classifying such `non-conventional' minerals represents a challenge to usual mineral definitions, which focus largely on inorganic structures, this overview highlights the striking similarity of organic minerals to artificial organic and metal–organic materials, and shows how they can be classified using the principles of coordination chemistry and crystal engineering.