Fulgurite (Lightning Glass, Blitzroehre Lechaterite), elongated shape

Surprising feature of nature created by lightning: (derived from the Latin root word "fulgur", meaning lightning) is formed by blossoming of electricity and silica when a thunder bolt of lightning strikes a dune of sand and such creates glassy crystal formations. from Great Erg, Algeria: It is a beautiful glassy silica (quartz) mineral (lechatelierite) fused in the heat from a lightning strike and locally melting the sand.