The belief that mines are haunted is an ancient and universal one, probably arising from the many eerie sounds and echoes that are heard in them and the perpetual gloom, which stimulates belief in apparitions. Sometimes the haunting specters are gigantic creatures with frightful fiery eyes. Such was the German "Bergmönch, a terrible figure in the garb of a monk, who could, however, appear in ordinary human shape to those towards whom he was well-disposed."
Frequently weird knockings were heard in mines. In Germany these were attributed to the Kobolds, small black beings of a malicious disposition. White hares or rabbits were also seen at times. The continual dangers attending work underground have been productive of many supernatural "warnings," which generally take the form of mysterious voices.
In the midland counties of England, the "Seven Whistlers" were well known, and miners paid solemn attention to their warnings. A light blue flame settling on a full coaltub was called "Bluecap," and his work was to move the coaltub toward the trolleyway. Bluecap did not give his services for nothing. Every two weeks his wages were left in a corner of the mine and were duly appropriated. A more mischievous elf was "Cutty Soames," who would cut the "soams" or traces yoking an assistant putter to the tub.
Basilisks, fearsome monsters whose terrible eyes would strike the miner dead, were another source of dread to the worker underground. These, as well as other mysterious foes who dealt fatal blows, may be traced to the dreaded, but by no means ghostly, fire-damp or perhaps to underground lizards.
Mines of precious metals were believed to be even more jealously guarded by supernatural beings. Gnomes, the creatures of the earth element, were the special guardians of subterranean treasure, and they were anxious to defend their province. Mines containing precious stones were equally well looked after. The Indians of Peru declared that evil spirits haunted the emerald mines, while a mine in the neighborhood of Los Esmeraldos was said to be guarded by a frightful dragon. It has also been believed that the poisonous fumes and gases that often destroy the lives of miners were baleful influences radiated by evil spirits.
Other stories of haunted mines are linked to legends of secret underground temples of occultists.
(See subterranean crypts and temples )