The fast growing markets for electric vehicles and wind power are putting a huge strain on the supply of the rare earth metals. Of these neodymium is responsible for the greatest amount needed for the construction of the magnets needed in making these. However, in along with each new neodymium magnet dysprosium and terbium are added to improve the high temperature properties. The problem is that there is a far vaster supply of Nd than either Dy or Tb so that even though the percentage that goes into each magnet may be relatively small compared to the whole the big disparity in their availability has an outsize effect on the cost of these metals.

From 2018 to 2022 the price of dysprosium tripled but that of terbium has gone up five-fold in the same time period. This currently makes terbium the most expensive of all the rare earth metals, easily surpassing lutetium, the long-time champ on this front. It’s especially worrying because there are no alternative substitutes but, on the other hand, increasing production is not a simple matter either. The net result is that there is every expectation that the price of these commodities will grow in tandem with the growth in the EVs and green energy sectors.

This is not good news for any of us. As the cost of acquisition increases there are fewer who can afford these samples. Cold comfort, I know, but expensive though terbium has become today’s high cost will likely seem a good deal in retrospect.