What does it mean to see jems in your dream?

This question is difficult to answer, because "jems" is not a Word in common English. It might be a misspelling of "gems," which are jewels. In that case, the gems represent items of great value. But the meaning of the dream would depend on what is done with those gems in the dream, who has them, how the dreamer feels when seeing or holding or losing the gems, and so forth. See attached link for more information about the way dreams communicate.