How Tektites are formed by Meteorite Collision Impacts?

The word Tektite has been taken from a Greek word "Tektos or melted" . People have been having a kind of fascination about glass products since centuries. The glass found in Afghanistan is famous as "mountain glass" . Similarly is the case with Libyan Glass. It were Chinese around 900 BC , who described the tektites thoroughly. In a book of Liu Sun, during T' and dynasty, it was written (after translation) 

 “Notes on the Wonders Beyond the Nanling Mountains in Kwangtung”.

Tektite remained enigma still 1973. It was Alfred Lacroix, a researcher from the Musee National d’Histoire Naturelle, who described the Tektite technically right after finding large Tektite deposits in Indonesia. Later, another locality was found about Tektite deposits existed at Ivory Coast. These findings increased the interest of scientists about Tektites. The researchers started to define and test tektites. Some researchers linked the Tektite with the Moon.

Experts and scientists have suggested a possible extraterrestrial connection to Tektite. Nonetheless, the prevailing scientific consensus is that this stone originates from the rapid melting and subsequent cooling of terrestrial rocks. These rocks are believed to have been vaporized by the intense impact of comets, asteroids, or meteorites on the Earth's surface.

What is Tektite?

Tektites are basically glass. A silica glass formed by hypervelocity activity. Tektites occur due to hypervelocity meteorite collisions with terrestrial rocks on Earth's surface. The size of tektite is almost of walnut.

The refractive index of Tektites range from 1.48 to 1.51. The specific gravity is from  2.3 to 2.5. The tektite glass is almost anhydrous in contrast to volcanic glass. Tektite color and age can be different depending on the land or origin where they are found. The age of tektite usually goes from 35.5 million to 750,000 years  old. 

Tektites are characterized by their composition rich in silica. Australasian types typically consist of around 70% silica, while Libyan glass surpasses this with an impressive 98% silica content. What sets them apart from granitic rocks, which are acidic igneous in nature, is their reduced levels of soda, potash, along with elevated amounts of lime, magnesia, and iron. Unlike conventional volcanic glasses found in space, tektites usually lack crystals or microlites, distinctive features commonly observed in such materials.

 Mostly scientists think that tektites are formed by rapid heat and sudden cooling effects of quartz rich soils and rocks. Impact of meteorites or asteroids, the large terrestrial  bodies are enough to melt soils, rocks, minerals and help in forming tektite. 

 Alternative Hypotheses about  Tektite

In the early days of research, the prevailing notion posited tektites as byproducts of terrestrial volcanic activity, their unique shapes attributed to erosion caused by wind or water. However, subsequent investigations have cast doubt on this hypothesis, noting the absence of typical signs of abrasion despite the surface resemblance to ablated materials.

The presence of abrasion is also evident in gemstones embedded within sedimentary rocks, where the combined forces of wind, water, and rocks contribute to their distinct shaping. Ablation, meanwhile, describes the process whereby molten surface layers of meteorites undergo reshaping through vaporization during their descent through Earth's atmosphere.

Numerous hypotheses exist concerning the genesis of tektites, with some even suggesting human intervention. Yet, a scrutiny of their chemical composition and age refutes such claims. Tektites significantly predate human civilization, their ages far predating the emergence of human technological prowess around 6000 B.C.

Properties of Tektites

• Distribution of age
•  geological ag.
• Physical properties
• chemical compositions.
• Shape of tektites
• melting features of tektite specimens
• Internal features

Tektites are discovered worldwide in designated regions known as strewn fields, found on all continents except Antarctica. These formations have occurred at various points in Earth's history. For instance, the North American strewnfield dates back approximately 35.4 million years, predominantly consisting of splash-form tektites. Another example is the Czech Republic strewn field, dating back 14.6 million years and containing tens of thousands of tektite specimens. Moldavites, found in the North American region, are a notable subset. Additionally, the Australasian strewn fields span from South China.

Chemical Composition of Tektites

The naturally formed glass varieties contrast with Tektites in terms of their physical and chemical characteristics. Tektites commonly present a shiny black or yellow-brown to dark brown appearance. Moldavites showcase a deep green coloration, while Libyan desert glass exhibits hues ranging from greenish-yellow to straw-yellow.

Hardness of Tektites: 6 to 7 on Mohs' scale

Tektites have mostly have silica (SiO₂) content. Silica content range is different from moldavite, Libyan glass or ivory coast tektites.

Though obsidian also has high content of silica such as up to 80%. However, there are various other features which can differ obsidian from tektites. 

Tektites harbor minuscule specks of lechatelierite, an exceedingly uncommon variant of silica glass forged solely through the extreme temperatures and pressures incurred by the liquefaction of quartz crystals. These distinguishing traits prompt us to identify tektites as products of meteorite impacts. Unlike obsidian or naturally occurring glass, lechatelierite within tektites commonly exhibits air pockets, signifying the exacting pressures requisite for its creation. This demarcates tektites and underscores their exceptional genesis.

Tektite Formula: Silica (75%) + Al, Fe, Ca, Na, K, Mg, Ti, Mn.
RI: 1.46-1.54
SG: 2.21-3.40
Luster:         Viterous
Transparency:    Transparent to Opaque
Optics:   Isotropic; N = 1.46-1.54.
Color:  Blackish Yellow, Green, Greenish Brown, Brownish Yellow, Brown in Moldavites, greenish yelloww, colorless.
Fracture: Conchoidal
Crystallography: Amorphous (tektites are natural glasses).
Pleochroism: None

Division of Tektites

• Moldavite
• Microtektite
• Australite
• Bediasite
• Indochinite
• Philippinite
• Uruguaite
• Bikolite
• Billitonite
• Chinite
• Darwin Glass
• Georgiaite
• Irghizite
• Ivorite
• Zhamanshinite

Classification of Tektites Based on External Form

Type A: Muong Nong Tektites

Type A, also referred to as Muong Nong tektites, exhibit a robust external structure. Characterized by chunky formations, they often display variations in bubble distribution and internal layering. These tektites were initially identified in 1935 by Lacroix, deriving their name from Moung Nong, Laos, the location of their discovery.

Type B: Splash-Form Tektites

Type B tektites, classified as "splash-form," manifest in diverse shapes, including spheres, ellipsoids, rods, teardrops, dumbbells, and boats. Their internal composition demonstrates contouring, rolling, or bending due to fluid dynamics during the molten phase.

Type C: Heat-Induced Tektites

Type C tektites emerge as a result of localized heat exposure, leading to the loss of mass through ablation or the reshaping of material to form a flange derived from the anterior side. These tektites are frequently identified as Australites and Javanites.