igneous

Tektite (Indochinite)

Tektite (impactite), primarily high-silica glass (SiO2)

Hardness: 5.5-6.5 (Mohs); Color: Generally black, but translucent olive-brown on thin edges; Luster: Vitreous to dull; Crystal Structure: Amorphous (glassy); Cleavage: None (conchoidal fracture); Specific Gravity: 2.3-2.5

Hardness: 5
Color: Generally black, but translucent olive-brown on thin edges
Luster: Vitreous to dull

Identified February 24, 2026More igneous →

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Physical properties

Formation & geological history

Formed roughly 780,000 years ago during a massive meteorite impact in Southeast Asia. The impact ejected terrestrial silica-rich soil into the upper atmosphere, where it melted, flash-cooled in the vacuum of space, and rained back to Earth as glass droplets.

Uses & applications

Primarily used for gemstone carvings, jewelry (pendants/rings), and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Tektites contain almost no water, making them significantly drier than volcanic glass (obsidian). This specific type, the Indochinite, belongs to the largest strewn field on Earth, covering parts of China, Thailand, Vietnam, and Australia.

Field identification & locations

Identify in the field by its pitted, 'dimpled' surface (regmaglypts) and conchoidal fracture. Unlike obsidian, it will not have flow bands and is rarely found near volcanoes. It is common in the gravel beds of Southeast Asia.

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Fluorapatite (Ca5(PO4)3F)

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Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous

Magnetite

Iron(II,III) oxide (Fe3O4)

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Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

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Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

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Magnetite

Magnetite (Fe3O4)

mineral