Tektite – Tanzanian
This mysterious gem has been called many names including Green Obsidian, African Moldavite, Tanzanian Tektites, Green Volcanic Glass and even just glass. One source says the Tanzanian natives call it Obsidianite. It is reported to be found in alluvial deposits and in a river bed at the base of Mt. Kilamanjaro. Some say it is a natural volcanic glass, some argue that it is man-made glass, others claim it is of meteoric origin similar to Moldavite. Calling it “African Moldvite” is incorrect however, since Moldavite only comes from the Moldau River reqion of the Czech Republic. Where ever this material comes from or however it was formed, it is a stunning gem of the finest Tsavorite green color found anywhere. The green Tektites usually contain gas bubbles and “swirl” like inclusions typical of other Tektites.
Tanzanian Tektites may be similar to other Tektites such as Indochinites, Libyan Desert Glass and Moldavite. Tektites may be Meteoric Silica Glass as a result of the impact of a meteor on Earth. Tektites are usually found in association with meteor impact craters or suspected ancient craters. Their origin is not fully understood. The leading theory, the “Meteorite Impact Theory”, is that when a meteorite hits the Earth, the heat and pressure of the impact are so great that it causes rock and sand to be fused into glass or Tektites.
| Crystallography: | Amorphous (natural glass) |
| Crystal Habit: | n/a |
| Cleavage: | None |
| Fracture: | Conchoidal, Sub-conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.5 – 6.5 |
| Density: | 2.33 – 3.00 (g/cm3) |
| Radioactivity: | Not Radioactive |
| Color: | Dark Brown, Black |
| Transparency: | Translucent to Opaque |
| Luster: | Vitreous |
| Refractive Index: | 1.46 – 1.54 Isotropic |
| Birefringence: | 0.00 (Isotropic) |
| Dispersion: | n/a |
| Pleochroism: | n/a |
