I cannot speak for the organic matter but only for the inorganic part of geosciences (mineralogy) with emphasis placed on sediments and alteration minerals (supergene/hypogene). TEM can successfully be used for the wide range of Mn-oxide hydroxides, clay minerals (mica, kandite-group (kaolinite vs. halloysite) minerals, chlorite s.s.s., smectite s.s.s.) , calcareous and siliceous nano- fossils in , e.g., tripolite and diatomaceous sedimentary rocks , Ti oxides and the wide range of APS minerals (aluminum-phosphate-sulfates).