rld. Gibeon, Nantan, Canyon Diablo meteorites. Moldavite and tektite specimens. Moldavite jewelry set in sterling silver.
the Latin Fulgur, lightning) are produced by lightning striking exposed
surfaces. These Fulgurites have been found at the feet of sand dunes
of the Great Sand Sea, in the southwest of Egypt. Their tubular shapes
are typical of lightning striking sands. On rocks, they may have different
shapes. It has been estimated that each flash of lightning releases
an average energy of 1 billion Joules. Air temperatures may reach
momentarily 10,000 degrees K, even sometimes 30,000 degrees K. The
peak currents measured range from 10 kA to 100 kA but they last only
a few microseconds. This high energy will melt or vaporize the sands
or rocks with formation of amorphous glass, named by A. Lacroix who
studied this phenomenon since 1915: Lechatelierite (after the French
mining engineer, Le Chatelier.) Tubular Fulgurites are known that
exceed 8 meters but their recovery as a whole is impossible; they
are very fragile and are usually found in pieces of 10 to 15 cm, with
diameters ranging from 5 to 20 mm.