Mineraloid (Impact glass)

Tektite (specifically Indochinite)

Tektite (Natural silica glass)

Hardness: 5.5-6.5 on Mohs scale; Color: Black, dark bottle green/brown (translucent on thin edges); Luster: Vitreous to dull; Crystal structure: Amorphous (non-crystalline glass); Cleavage: None/Conchoidal fracture; Specific gravity: 2.3-2.5.

Hardness: 5
Color: Black, dark bottle green/brown (translucent on thin edges)
Luster: Vitreous to dull

Identified March 29, 2026More mineraloid (impact glass) →

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Physical properties

Formation & geological history

Formed from the molten ejecta of terrestrial rock following a high-energy meteorite impact. This specific Indochinite type originated from an impact approximately 780,000 years ago in Southeast Asia (Australasian strewn field).

Uses & applications

Used primarily for gemstone collecting, jewelry (faceted or wire-wrapped), and metaphysical/spiritual purposes (often called 'fire pearls').

Geological facts

Tektites contain almost no water (less than 0.005%), making them much drier than any volcanic glass like obsidian. The pitted surface (regmaglypts) is caused by aerodynamic ablation as the molten material hurtles back through the atmosphere at hypersonic speeds.

Field identification & locations

Identify by looking for the 'orange skin' pitted surface, conchoidal (glassy) fractures, and lack of bubbles common in slag. Found mainly in the 'strewn fields' of Thailand, Vietnam, and Cambodia. Collectors should look for aerodynamic shapes like teardrops or buttons.

Other mineraloid (impact glass) specimens

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Tektite (Indochinite)

Tektite (High-silica natural glass)

mineraloid / impact glass

Tektite (Indochinite)

Tektite - High-silica amorphous glass (SiO2 + Al2O3)

mineraloid

Tektite (Indochinite)

Tektite (High-silica impact glass)

mineraloid

Sea Glass (often mistaken for Gemstones)

Amorphous Silica (SiO2) with trace additives

mineraloid

Moldavite

Silica glass with small amounts of aluminum, iron, and other elements

Mineraloid / Tektite

Tektite (likely Australite)

Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)

Mineral (specifically a mineraloid)