Metal parts are sometimes passivated with hydrogen sulfide. This coating is passivated by chromate salts. Class II - Iron particles originating in-situ on unpassivated or improperly passivated stainless steel surfaces. Be and Mg are passivated by an impervious layer of oxide. Silver can be passivated by exposition to iodine vapors, forming a layer of silver iodide. The nanoparticles are passivated with organic capping agents, providing solubility and thus solution processability. A spacecraft moved to a graveyard orbit will typically be passivated. Internally graphitized tubes via acetylene thermal decomposition are passivated. Finally, the workpiece, whether passivated or not, is dried. Iron bar surface is passivated as long as the pH value is higher than 10.5. Metals that are passivated by concentrated nitric acid are iron, cobalt, chromium, nickel, and aluminium. The passivated magnesium flash powder is stable and safe to store. The separated cryogenic stage was subsequently reoriented and passivated.