Morphology and Composition of Fulgurite and Comparison with Similar Natural Materials

Fulgurites are natural glass material which is formed when lightning strikes and melts the ground and the super high temperature fuses and vitrifies mineral grains. The fulgurite was seldom studied in China due to the rareness of the specimens. By using several new technologies such as CT scanning, 3-D reconstruction of the interior structure and electron probe microanalysis, the results reveal the detailed morphology of both the external and interior structures of the fulgurite as well as its mineral composition. Its external surface is complex and coarse while the internal surface is bright and different from the internal surface in color. The internal surface is full of foramina, and can be classed into three types:fully run-through, partially closed, and completely closed. The fulgurite has the dominant composition of SiO₂, with only small proportion of other metal elements. It also was compared with volcanic glass and tektite and determined that a tubular structured stone from Inner Mongolia is not fulgurite. This paper provides some basic data for future study and application of the fulgurite.