What is "fairy of the mine"

Fairy \Fair"y\, n.; pl. Fairies. [OE. fairie, faierie, enchantment, fairy folk, fairy, OF. faerie enchantment, F. f['e]er, fr. LL. Fata one of the goddesses of fate. See Fate, and cf. Fay a fairy.] [Written also fa["e]ry.]

1. Enchantment; illusion. [Obs.]
   --Chaucer.

   The God of her has made an end, And fro this worlde's fairy Hath taken her into company.
   --Gower.

2. The country of the fays; land of illusions. [Obs.]

   He [Arthur] is a king y-crowned in Fairy.
   --Lydgate.

3. An imaginary supernatural being or spirit, supposed to assume a human form (usually diminutive), either male or female, and to meddle for good or evil in the affairs of mankind; a fay. See Elf, and Demon.

   The fourth kind of spirit [is] called the Fairy.
   --K. James.

   And now about the caldron sing, Like elves and fairies in a ring.
   --Shak.

   5. An enchantress. [Obs.]
   --Shak.

   Fairy of the mine, an imaginary being supposed to inhabit mines, etc. German folklore tells of two species; one fierce and malevolent, the other gentle, See Kobold.

   No goblin or swart fairy of the mine Hath hurtful power over true virginity.
   --Milton.