Tektite (Indochinite)
Impact Glass var. Indochinite · Meteoritic Material / Collector Mineral
Crystal System
Amorphous (Non-crystalline material with no internal structure)
Mineral Group
Natural Glass (Tektites)
Chemical Formula
SiO2 (~75%) + Al2O3, FeO, MgO, K2O (variable high-silica glass)
Formation Process
Impact origin; terrestrial Earth rock melted and vaporized by a massive meteorite impact, ejected into space, and solidified during re-entry back into Earth's atmosphere.
About This Crystal
Opaque to translucent dark brown to black glass with a pitted or 'regmaglypted' surface. The texture is characterized by flow lines, bubbles, and aeronautic shapes (splashes, dumbbells, or teardrops) caused by atmospheric friction.
Physical Characteristics
Color: Black/Deep Brown; Streak: White to Colorless; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.3–2.5; Luster: Vitreous to dull; Fluorescence: None.
Optical Properties
Isotropic (singly refractive) due to being glass; Refractive Index: 1.48–1.51; No pleochroism or birefringence.
Hardness & Durability
Origin Region
Southeast Asian Strewn Field (Thailand, Vietnam, Cambodia, Laos, China)
Hardness & Durability
Mohs Hardness: 5.5–6.5; Brittle; Fair stability but sensitive to rapid temperature changes and physical shock.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners or harsh chemicals. Store separately to prevent scratching from harder minerals like quartz.
Rarity & Value
Common (within its specific strewn field); value is determined by shape (teardrops are prized), weight, and surface texture. Generally affordable, ranging from $5 to $100 depending on size.
Special Characteristics
Possesses distinct pitting known as 'pocking' and 'cupules' formed by aerodynamic ablation. Unlike volcanic obsidian, tektites are essentially water-free (anhydrous).
Lore & History
Historically used as talismans in Southeast Asia. In metaphysical lore, it is believed to enhance communication with other worlds and facilitate spiritual growth through its 'extraterrestrial' energy.