In the modern Bermuda Triangle, on the ocean bottom where the  ruins of Atlantis now exist, the energy build-up in the sunken  and damaged Fire Crystals can periodically trigger  de-materializations of anything in the area.

One of the most detailed descriptions of the Atlantean use of a mysterious instrument called the Great Crystal was given by  Edgar Cayce, who mentioned it many times.

The crystal, he said  was housed in a special building oval in shape, with a dome that  could be rolled back, exposing the Crystal to the light of the sun,  moon and stars at the most favorable time.

The interior of the building was lined with non-conducting  metal or stone, similar to asbestos or bakelite, a thermosetting  plastic.

The Crystal itself, which Cayce also called the  Tuaoi Stone, or Firestone, was huge in size, cylindrical in  length, and prismatic in shape, cut with six sides. 

 Atop the crystal was a moveable capstone, used to both  concentrate incoming rays of energy, and to direct currents  to various parts of the Atlantean countryside.

It appears that the Crystal gathered solar, lunar, stellar,  atmospheric and Earth energies as well as unknown elemental  forces and concentrated these at a specific point, located  between the top of the Crystal and the bottom of the capstone.

The energy was used for various purposes. In the beginning  it was used as purely a spiritual tool by initiates who could  handle the great energy.

 The early Atlanteans were peaceful  people. As they developed more physical material bodies,  they used the crystal to rejuvenate their bodies and were  able to live hundreds of years while maintaining a youthful  appearance.

Later the Great Crystal was put to other uses. Currents of energy  were transmitted throughout the land, like radio waves, and  powered by these, crafts and vehicles traversed the land,  through the sky and under the sea at the speed of sound. 

By utilization of other currents originating from the Great  Crystal, the Atlanteans were also able to transmit over  great distances the human voice, and pictures, like modern  television. In the same manner, even heat and light could  be directed to specific buildings or open arenas, giving  illumination and warmth by seemingly invisible means.