Gadolinium-154

Gadolinium-154 is an isotope of the chemical element gadolinium.

In 3191, Commander Paul Stamets detected trace amounts of gadolinium-154 on a "library card" left behind by Doctor Marina Derex. As gadolinium-154 was not found on Betazed, he hoped that it could lead him to the card's point of origin. However, this line of inquiry yielded too many possibilities to be feasible. (DIS: "Erigah")