How to identify Tektite

To correctly identify Tektite (Tektite), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Typically black, dark brown, or dark green. Rarely yellowish-green (moldavites).

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) to dull.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth to highly sculptured, often with pits, grooves, and flow lines. Can be aerodynamic in shape.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Amorphous (no crystal structure).

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None, exhibits conchoidal fracture.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in strewn fields associated with large meteorite impact events, often in unconsolidated sediments like sands and gravels.

Key Facts

Hardness

5.5-6.5 on Mohs scale

Specific Gravity

2.3-2.8 g/cm3

Crystal System

Amorphous

Color

Black, dark brown, dark green (rarely yellowish-green)

Luster

Vitreous to dull

Transparency

Opaque to translucent (especially on thin edges)

Fracture

Conchoidal

Cleavage

None

Composition

Primarily silica (SiO₂, 65-80%), with varying amounts of Al₂O₃, FeO, MgO, CaO, K₂O, Na₂O, and TiO₂. Characteristically very low water content (<0.02 wt%).

Physical characteristics

• Crystal Habit: Amorphous, typically found as aerodynamically shaped objects (spheres, dumbbells, teardrops, buttons, lenses, irregular fragments).
• Cleavage Type: None
• Fracture Type: Conchoidal, producing sharp, curved surfaces.
• Tenacity: Brittle
• Luster Type: Vitreous (glassy) to dull.

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