Methods for forming colloidal metal chalcogenide nanoparticles generally include forming soluble inorganic metal chalcogen cluster precursors, which are then mixed with a surfactant and heated to form the colloidal metal chalcogenide nanoparticles. The soluble inorganic metal chalcogen cluster precursors are generally formed using a hydrazine-based solvent. The methods can be used with main group and transition metals.