The　hydrothermal　synthesis　of　zeolite　from　chemical　Al/Si　source　in　the　presence　of　structure　directing　agent　is　considered　to　be　a　resource　extensive,　energy　consuming,　and　environmental　unfriendly　process.　Herein,　we　report　a　novel,　cost-effective,　and　eco-friendly　synthesis　for　the　preparation　of　ZSM-5　zeolite　from　silicon-rich　diatomite　and　aluminum-rich　rectorite　minerals　in　the　absence　of　organic　structure-directing　agent　and　chemical　Al/Si　source.　Synthesis　factors　(SiO2/Al2O3,　Na2O/SiO2,　and　H2O/SiO2　molar　ratios　along　with　seed　content)　and　crystallization　behavior　were　systematically　investigated,　providing　fundamental　knowledges　on　the　formation　of　ZSM-5　from　natural　minerals.　Synthesis　under　the　optimized　conditions　(SiO2/Al2O3　ratio　of　around　38,　Na2O/SiO2　ratios　of　0.12–0.15,　H2O/SiO2　ratios　of　15–25,　and　seed　content　above　0.5%)　led　to　production　of　highly　crystalline　ZSM-5　zeolite　with　hexagonal　prism　morphology　and　large　surface　area.　Various　characterization　techniques　tracking　the　products　at　different　crystallization　times　revealed　that　the　crystallization　process　consisted　of　three　stages:　short　induction　stage　(0–6　h),　rapid　growth　stage　(6–18　h),　and　stable　growth　stage　(18–36　h).　Moreover,　the　synthesized　ZSM-5　crystals　can　be　used　as　effective　seed　for　producing　the　next　generation　of　ZSM-5　zeolite.　©　2018