If you’ve ever looked at a thick pane of glass edge on you’ve probably noticed it’s as green as an emerald. For an executive’s desk that might be totally fine but in many other applications a green tint is undesirable. Cerium has been put to use for its ability to mop up the trace contaminants that give glass this color and neutralize the effect, yielding glass fit for optics.

Cerium’s relationship with glass extends to the polishing stages also where it ranks as the most popular polishing agent. Why reach for an exotic substance when a more conventional abrasive is surely much cheaper and accessible? Well, as it turns out cerium (as an oxide) is not only a great polisher but it also lowers glare, so two for the price of one.

Atmospheric oxygen makes short work of the pure metal so keeping it in its metallic state invariably requires ampuling under a noble gas like argon, as is the case in these carefully prepared samples.