A black hole of light only, has its name - Kugelblitz. When you have enough dense light, a black hole is normally formed and has this cool name - Kugelblitz!
The black hole of almost exclusively neutrinos, what is its name? I googled a little but haven't found anything yet.
Reminds me of this paper,
it was proposed that a black hole could be artificially created by firing a huge number of gamma rays from a spherically converging lasers. The idea is to pack so much energy into such a small space that a black hole will form.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.