Fulgurite or lightning tube, thunder stone. / sagitta fulguris. / pierre detonnerre (title on object), a tube of molten sand or rock created during a lightning strike. Here referred to as a 'thunder stone'. Top right the Latin name, numbered top left: 27. Part of the seventh album with drawings of reptiles, amphibians and natural history ensembles. The seventh of twelve albums with watercolors of animals, birds and plants, known around 1600, commissioned by Emperor Rudolf II. With explanations in Dutch, Latin and French, minerals and metals, Anselmus Boetius de Boodt, Praag, 1596 - 1610, paper, watercolor (paint), deck paint, ink, pen, h 110 mm × w 116 mm