Formation
Double-terminated crystals form in evaporated clay pockets of free-floating liquid. The evaporated liquid leaves crystals that are perfectly formed with terminations on both ends. The terminations are formed when the six faces of quartz join together. They are found in sedimentary rock formed by subterranean marine deposits. This makes them rare, because most crystals grow on quartz or sandstone matrix.
Healing Uses
Double-terminated crystals are thought to have healing powers because they are able to draw in, hold and release energy from both ends. The crystals can absorb negative energy and help break old patterns. Some people place double-terminated crystals over organs of the body that are not functioning properly, to release negative energy. People have used crystals to help people overcome addiction and to rejuvenate the face by relieving stress lines.
Metaphysical Powers
Double-terminated crystals are thought to enhance telepathic ability when placed on the "third eye." The crystals are also said to enhance the sleeping and dreaming experience. It is said that if you place one of these crystals under your pillow, it will make your dreams more lucid and make them easier to recall. It is also believed that a double-terminated crystal can balance the energy between two people if they sit facing each other holding the crystal. There is no scientific evidence that crystals have such powers.
Herkimer Diamonds
The rarest of all of the double-terminated crystals are Herkimer diamonds. These double-terminated crystals are often mistaken for diamonds because of their luster and shape. They get their name from Herkimer County in New York where they were first found, but they have also been found in Spain and Mexico. They are found embedded in dolomite rock as free-standing crystals.