Fulgurite (a variety of lechatelierite) from the Bouarfa area, Morocco. This specimen forms a half-tube.
Miniature Specimen: about 1.6" long x 0.4" diameter (40mm x 10mm)
Fulgurites (from the Latin fulgur, meaning "lightning") are natural tubes, clumps, or masses of sintered, vitrified, and/or fused soil, sand, rock, organic debris and other sediments that sometimes form when lightning discharges into the ground. Fulgurites are classified as a variety of the mineraloid lechatelierite.