When two boys stumbled on an unusual rock near Winans Lake, Michigan, they thought they had found what appeared to be at 1st glance a huge dinosaur leg bone. Scientists from the Museum of Palaeontology at the University of Michigan went out to investigate, only to locate that the 15-footlong white, green, and grey object was the worlds largest fulgurite, Latin for thunderbolt. It’s a tube shaped glob of glass that formed when a powerful lightning bolt struck the ground. The glassy tubes of lightning-fused rock are most widespread on mountaintops, almost certainly because their high altitude attracts a lot more lightning strikes. Although fulgurites might form from any kind of rock, the largest happen to be created from unconsolidated (loose) sand.
For centuries, scientists have identified that huge lightning bolts, which can attain temperatures numerous times those on the surface of the Sun, can melt or vaporize rocks they strike. However, until recently, the chemical and physical processes within the formation of fulgurites were largely unknown. Additionally, the studies revealed the presence of two metallic minerals that had never ever prior to been found to occur in nature. The fulgurite also was found to become among the most chemically decreased (oxygen-removed) natural substances known on Earth.
Electron microscope analysis of metallic globules embedded inside the fulgurite glass showed them to become composed of a variety of iron and silicon metal compounds previously identified only to exist in meteorites. Apparently, the lightning bolt somehow chemically altered the original iron oxides within the ground, to an even higher extent than those found in most meteorites. The fulgurite was also enriched in gold, which the lightning apparently scavenged from the surrounding soil and concentrated inside the glass.
A glass of a diverse sort is in the form of tektites; the name is derived from the Greek tektos, meaning molten. They’re glassy bodies created from the melt of a big meteorite impact. Over half the rock ejected by an impact remains molten inside the rising plume and falls back to Earth as tektites. Significantly of the high-flying material is identified to be deposited halfway about the globe. Massive meteorite impacts dump millions of tons of tektites over vast places named strewn fields.
Tektites range in colour from bottle-green to yellow-brown to black; they were once prized as ornaments by the Cro-Magnon, our ancient human ancestors. Tektites are normally small, about pebble-sized, although some have been recognized to become as huge as cobbles. Tektites are chemically distinct from meteorites and have a composition comparable to that of the volcanic glass obsidian but contain a lot much less gas and water. They also lack microcrystals, a characteristic uncommon in any kind of volcanic glass.
Tektites comprise abundant silica related to the pure quartz sands utilized to manufacture glass. Indeed, tektites appear to become natural glasses formed by the intense heat generated by a large meteorite impact. The impact flings molten material far and wide; even though airborne, the liquid drops of rock solidify into numerous shapes from irregular to spherical, which includes ellipsoidal, barrel, pear, dumbbell, and button shapes. They also have distinct surface markings that apparently formed even though solidifying during their flight by way of the air.
Mysterious glass fragments strewn over Egypts Western Desert seem to become melts from an enormous impact about 30 million years ago. Large, fist-size, clear glass fragments found scattered across the Libyan Desert had been analysed for rare trace elements, which indicated that the glasses had been produced by an impact into the desert sands. The huge fragments of glass showed extraordinary clarity.
The impact force also generates really high temperatures that fuse sediment into little glassy spherules resembling volcanic glass. Thick deposits of sand-size spherules scattered all through the world document the great meteorite bombardments during the Earths whole history.
Joseph Kieffer
http://jewelryuk.org
from: http://hand-crafted-jewelry.com