Origins[]
A Bluecap is a mythical fairy or ghost in English folklore that inhabits mines and appears as a small blue flame. They are mostly associated with the Anglo-Scottish borders.
Appearance[]

Unlike a Tommyknocker, which is gnome-like in appearance, a Bluecap usually appears as a small blue flame similar to a [hitodama]. Sometimes they appear as a being made out of blue fire or a small fairy that gives off a blue glow.
Behavior[]

Bluecaps help miners find rich veins of ore. Like Tommyknockers, they warn of cave-ins and miners leave offerings of food or money for them. They only take what is owed, never more or never less. They were known for taking silver if they were short-changed and leaving silver in the mine if overpaid.