Jakmanite is a radioactive mineral that is not normally picked up by the sensors of a Galaxy-class starship.

Furthermore, along with invidium, saltzgadum, selgninaem, and lucovexitrin, it is one of only five undetectable substances that can exist in a nitrogen-oxygen atmosphere, and which can alter the molecular structure of glass.

Jakmanite has a half-life of about fifteen seconds and was thereby ruled out as having caused the malfunctions aboard the USS Enterprise-D at the end of 2366, as there would not have been enough time to spread the substance all over the ship. (TNG: "Hollow Pursuits")

Minerals

Anorthosite • Antimonium • Bakrinium • Benamite • Beresium • Bernicium • Bilitrium • Boronite • Chrondite • Cormaline • Feldomite • Feldspar • Fortanium • Gallicite • Jakmanite • Jevonite • Kelbonite • Kemocite • Ladarium • Magnesite • Murinite • Neutronium • Nitrium • Noranium • Paralithium • Pergium • Regolith • Riddinite • Ryetalyn • Silithium • Styrolite • Talgonite • Topaline • Trellium • Tricyanate • Trimagnesite • Tritanium • Uridium • Vendarite • Zenite