To prepare a new kind of electromagnetic wave absorber, and improve the processing technology and accessional value of natural microcrystalline graphite minerals (NMGMs), reduced microcrystalline graphene oxide (rGO-M), a novel absorber with high absorption, low reflection and a wide absorption band, was prepared from NMGMs using a solvent-assisted thermal reduction method. Moreover, the as-produced rGO-M with adjustable electrical resistivity can be easily transferred into well distributed bulk materials by freeze-drying technology. These uniq...