Small fragments (usually 2.5–5.0 cm) of silica-rich, translucent black glass, found scattered over large areas (strewn-fields) in particular regions of the Earth. Most tektites exhibit ‘splash’ shapes (tear-drops, dumb-bells, etc.) indicating a rapid cooling and solidification during flight. They are thought to have formed as ejecta from cometary or meteorite impacts on to silicate-rich rocks, most likely terrestrial, although this is still a matter of some controversy. The material would have melted on impact, been thrown up into the atmosphere or space, and landed, resolidified, far from the site of origin. The ages of known tektites range from around 0.7 to 35.0 Ma. Microscropic tektites (microtektites) have been recorded from ocean sediments off the Ivory Coast, off southern Australia, and from the Indian Ocean.