Terbium may lurk in a remote corner of the periodic table and is unknown to the vast majority of the world by name but the metal is in permanently high demand as an essential ingredient in the making of LCD panels. Specifically, it makes up the green dots on the screens of your cell phone and PC which, along with blue and red phosphors, can from a distance blend into any of millions of colors. Due to its rarity and difficulty in extraction terbium is, ounce for ounce, two to three times as expensive as silver. Even at these heady prices terbium is often difficult to source in quantity as only two countries, Russia and China, are currently engaged in refining and trading in this semi-precious commodity.

Interestingly, various web sources repetitively cite that terbium is so soft that it can be cut with a knife. This is incorrect; a sharp steel knife will barely scratch pure terbium. Its true hardness is comparable to that of iron. Also, although terbium is relatively stable in air a freshly cut piece will eventually tarnish due to moisture in the air which reacts to form superficial oxides and hydroxides.

CAS 7440-27-9