It's mentioned specifically in the Kinunir supplement - "Lanthanum: A rare earth element, the first of the inner transition metals. VitalCT did not have a lanthanum hull grid. Only MT, T4 and now MgT. Zuchai crystals were introduced in A4.
A black globe could power your jump capacitors, but the rules state you still need fuel to jump.
to the construction of the inner coils of interstellar jump drive units." and in the Library Data A-M booklet. And a few other places within CT.
In HG it does specifically state that black globes can power the jump drive, but that the ship also needs jump fuel. However this is contradicted elsewhere in CT where it describes the process by which the ship rapidly consumes its fuel to power the capacitors to power the jump drive (and, of course, the Annic nova accumulators). Traveller is full of contradictions, but the idea that your fusion plant rapidly cycles through its' fuel to charge the capacitors isn't an idea that I (recall at least) being contradicted elsewhere in the literature. So, for me personally, I interpret the need for fuel when your capacitors are fully charged as one of the errors. I try to generally stay within each iteration of Traveller for a fair comparison of tech and explanations.