Indochinite tektite Freeform - Height: 75 mm - Width: 28 mm - 98 g - (2)

This is two Indochinites, a black tektite characteristic of the Australasian strewn field. Vietnamese Indochinites (Muong Nong type specimen for the largest).

Length: 75×25×25 mm and 55×15×15 mm; masses: 98 g and 20 g
Shape: elongated, fusiform/ellipsoidal — typical of Indochinites that take drop, dumbbell, or disc forms depending on their cooling trajectory

Age ~790,000 years

Major meteorite impact in Southeast Asia (crater presumed in southern Laos / northern Cambodia)

Instant fusion of terrestrial rocks (silica) projected into the atmosphere, followed by rapid cooling into natural glass

Strewn field
The largest in the world: covers ~30% of the Earth's surface (Australia, Southeast Asia, Indian Ocean)

Pitted surface (major feature)
The numerous cavities and pits visible across the surface are aerodynamic pittings: they form during the reentry of the molten glass droplet, where frictional ablation creates these characteristic impressions

Typical chemical composition of Indochinites
SiO₂: ~70–75%
Al₂O₃: ~12–15%
FeO: ~5–7%
CaO, MgO, Na₂O, K₂O: traces
Extremely low water content (< 0.02%) — distinctive signature of tektites
Mohs hardness: 5 to 6.5
Density: ~2.4 g/cm³
Regular pittings: the cavities should have melted/rounded edges, not mechanical fractures
Presence of lechatelierite (pure amorphous SiO₂) — evidence of fusion at very high temperature

Indochinites are found mainly in:
Vietnam (Yen Bai, Binh Phuoc provinces…)
Laos
Cambodia
Thailand