English: Billitonites (= indochinites) from Billiton Island (a.k.a. Belitung Island), Indonesia. (FMNH Me 2326, Field Museum of Natural History, Chicago, Illinois, USA)

Large & small impacts have affected Earth since its formation 4.55 billion years ago. Compared with the intensely pitted and cratered Moon, Earth has relatively few preserved impact craters, because they have been destroyed by water & glacial erosion. Impact events are accompanied by tremendous amounts of heat, resulting in melting of much of the ejected pulverized bedrock at ground zero. The melted material cools quickly, and falls back to Earth in the form of impact splash glasses (a.k.a. tektites). Tektites are principally composed of amorphous silica (SiO2). Broken surfaces show a conchoidal fracture. Tektites from different impact events are given different names.

Indochinites are black-colored, moderately common tektites from southeastern Asia that typically are subspherical to tear-drop shaped to dumb-bell shaped. They are found throughout the Australasian Tektite Strewn Field (a.k.a. Indochinite Tektite Strewn Field). This strewn field is huge - it's estimated to extend over 10% of Earth's surface. Indochinites have been found from Madagascar to Tasmania to South China. Samples from different geographic areas are often given different names (e.g., australites, thailandites, malaysianites, philippinites, billitonites, vietnamites), but they were all apparently formed by the same event. The impact crater has never been identified (it's been buried, or eroded away, or the impact event was airburst), but is thought to be in the vicinity of northern Vietnam, based on tetktite abundance patterns. The age of indochinites has been reported to be about 783 to 803 ka.