We get so many questions from customers and visitors; “What is the difference between a tektite and a meteorite?”  The question is a big one.  This article is going to give the quick answer to this common question and then focus on specific information on tektites.  There is a second article which addresses Meteorites.  It is the intention that by the time the reader finishes both articles, there will be a greater knowledge of both and perhaps a peaked interest to learn more!

The Quick Answer:

The difference between a meteorite and a tektite is that meteorite is a metallic or stony object or body that is the remains of a meteor that entered the earth’s atmosphere while tektite is a small, round, dark glassy object, composed of silicates, formed by the rapid cooling of meteorite fragments that hit the Earth.

Detailed Look Into Tektites:

Tektites are evidence that the earth was once continuously under siege by outer space. These small chunks of impact glass have an atmospheric entry count of two. First is the initial impact followed by melt of surface material, then propulsion into the atmosphere, then re-entry, more melting/shaping and eventually a second impact with terra firma. They often acquire aerodynamic shapes when they partially melt on their return journey. Their name comes from the Greek word ‘tektos’, meaning ‘molten’. The first written reference to tektites was about one thousand and fifty years ago, by Liu Sun in China, who gave them a name meaning ‘Inkstone of the Thundergod’.

Tektites are formed over a few separate stages. The first and foremost of the stages is the initial impact of a meteorite with silica rich soil. The silica rich soil part is important, because it’s the melting silicates and terrestrial material that are ejected by the meteor impact that classifies tektites as tektites and not meteorites. During ejection the molten blob will begin to shape because of the interference with the atmosphere upon exit. It is before re-entry that the tektite begins the cooling process and will re-enter the atmosphere as a cool chunk of ejecta, except for some of the really large chunks that will retain heat. The first of the ejected material will re-enter at the highest speeds and the pressure alone superheats them again and begins the deformation/shaping process. These initial bodies are apt to scatter further away from the source crater than bigger chunks nearest to the impact that have reduced velocity and less variation in shape. Once the tektite touches down again, the surface of the Earth and any surrounding water etches the glass as it cools and is weathered. Moldavites are a great example of this phenomenon as they are so aggressively pocked and flattened.

The most widely accepted hypothesis suggests that tektites are created from high velocity, low angle impacts on a soft, water and silica rich surface. These conditions provide the best chance of propelling molten particulates into the atmosphere for re-entry, satisfying the parameters that categorize an impact glass as tektites.

A general baseline for establishing the scientific parameters that qualify a tektite are as follows. The source impact crater must exceed 10 km in diameter, produce 300 km wide strewn fields, and the fields must be at a distance over 200 km, but not in excess of 5,000 km (11,000 km if microtektites), from the impact crater. These are ridiculously specific parameters, but these hold true for all of the tektites that science is aware of.

Tektites have been found only in certain parts of the world, spread over large areas called strewn fields, mainly in low latitudes. The three major areas are south-east Asia (especially Thailand and the Philippines), Australia; Caribbean-North America; and Ivory Coast, West Africa.

Other areas include the Czech Republic (Bohemia); Slovakia (Moravia); Aouelloul Crater, Mauritania, Africa; the Libyan Desert; Irgiz, C.I.S.; Dalat, South Vietnam; Laos; Kwantung province, China; and Malaysia.  The Ries Crater in Germany and the Czech Republic is the source crater of the Central European strewn field which produces the ever popular moldavite. This pitted green, translucent tektite is by far the most sought after of all tektites. It can present in a wide range of greens with varying sizes of pits from erosion and re-entry. While the exact impact location is still unknown, the area that contains Libyan Desert Glass is certainly large enough to have originated from a 10 km wide impact crater. It was discovered by scientists in 1932.

Microtektites are tiny particles of tektite dust found in deep sea sediment in the Atlantic and Indian oceans. They have the same composition as tektites from the North American and Australasian strewn fields.

Over 600,000 tektites have been found in south-east Asia (heaviest 15 kg) and about 100,000 in Australia (heaviest 0.4 kg). About 2,000 (heaviest 91 g) have been found in the Caribbean-North American strewn field; 55,000 (heaviest 0.5kg) from Bohemia and Moravia and 200 (heaviest 79 g) from the Ivory Coast, West Africa.

Australian tektites have been found right across southern Australia, mainly below 25 degrees latitude, particularly within an east-west belt extending over Northern Territory, Queensland, most of South Australia, Victoria, New South Wales, and Tasmania, and the southern parts of Western Australia.

Tektites are named geographically, i.e. Australites (Australia), Indochinites (Thailand & Cambodia), Thailandites (Thailand), Philippinites and Rizalites (Philippines), Javaites (Java), Billitonites (Billiton Island, Indonesia), Moldavites (Vltavins) from the Czech Republic and Slovakia, Bediasites (Texas, U.S.A.), Georgiaites (Georgia, U.S.A.), and Irgizites (Irgiz, C.I.S.).

Tektites are geologically young, with a range of about 300,000 years to 35 million years. Many Australites are 610,000 to 750,000 years old. The North American tektites have been dated at 34.5 million years, and the Libyan Desert glass at 28 million years. The Bohemian and Moravian sites are dated at 14.7 million years, Aouelloul Crater at 3 million years and Ivory Coast tektites at about 1 million years.

Tektites are made of opaque to translucent, green, brown, grey, yellow-grey or black glass. Moldavites are typically green, while Australites are usually black or dark brown.

Their chemical compositions are similar to both granite and impure sandstone (greywacke) or soils of these compositions, being high in silica (68-82%) with 10-14% alumina and lesser iron, magnesium, calcium, potassium and titanium. These components did not have time to combine and form crystals but cooled quickly to form a glass.

Tektites do not contain any water. They can be mistaken for obsidian or pitchstone (black volcanic glasses), but these will emit some water on strong heating. With a hardness of 6-7 on Moh’s scale, tektites will easily scratch window glass. They have a density range of 2.2 (Libyan glass) to 2.8 (Moldavites), but are usually 2.4 to 2.5 grams per cubic centimeter. This is a little lighter than quartz beach sand. Human built objects can be mistaken for tektites, particularly molten bottle glass, glass marbles, and black buttons. Many of these will not have the correctly-shaped rims, symmetrical structures or colors of real tektites, while others will be too heavy or too light.

Common Tektite Shapes

The shape of tektites are typically linked to the distance between the strewn field and the impact site. There are a number of factors at play in tektite shaping, but the two primary are size and velocity upon re-entry. Generally, larger post-impact ejecta won’t attain as great of heights as smaller bodies, but they will retain more heat over longer periods of time.

Sphere – These tektites are roughly spherical in shape and are thought to have formed nearest to the initial impact and are often found at the inner edge of the strewn field closest to the impact crater. They had less time at high temperatures to undergo any major changes in shape, aside from superficial rounding of the outer edges.

Flanged/Button – This variety of tektite looks a lot like buttons, where the outer edges hardened, while the inner projectile remained molten and was pushed through and up the outer ring by the air as it plummeted. These tektites begin re-entry as a sphere, but the insane velocity and pressure laterally compress them into misshapen plate-like forms.

Dumbbell (asymmetrical and symmetrical spheroidal splash form) – These molten objects spun on a central axis creating a dumbbell shape as they catapulted toward earth. When balanced, the centrifugal force will create an evenly symmetrical dumbbell shape. But when not evenly applied you will get an unevenly asymmetrical dumbbell shape. Dumbbell tektites are found with other splash form tektites in the middle of the strewn field.

Teardrop/Spindle (elongate spheroidal splash form) – Teardrop shaped tektites are often the result of the spinning force that creates dumbbell shaped tektites being too great for the central mass, so it splits in the middle and launches to earth like a spindle. These tektites appear toward the middle of the strewn field range as they undergo significant speeds, pressure, and forces.

Layered (Muong Nong) – Muong Nong tektites present in a layered form that is often heavily included with terrestrial minerals like baddeleyite. Layered tektites are found closer to the source impact crater and will be less misshapen or have less variation in shape than those that re-enter at the outskirts of the strewn field. Compositionally, these tektites show the greatest amount of both extraterrestrial and native Earth minerals. Libyan Desert Glass is a layered tektite.

Microtektites – Microtektites are the smallest of all the terrestrial material ejected upon impact. Often these will take almost any form as they are essentially at the whim of the winds after re-entry. These tektites typically demarcate the outer edge of the strewn field and are usually found in ocean sediment.

Tektite Types

In addition to their distribution, age, and physical and chemical properties, tektites may be subdivided into three distinct types on the basis of their external form.

Type A

A Type A Tektite (a.k.a. Muong Nong-type)

Also known as the Muong Nong-type, these tektites are often chunky or platy in external form, but often show evidence of internal compositional layering as well as variations in bubble content. Believed to be formed by puddles of molten glass, this tektite type was discovered in 1935 by Lacroix, they are named for the town of Muong Nong, Laos, located near where they were first found.

Type B

Or “splash-form” tektites, consisting of specimens, when unbroken, can be shaped as spheres, ellipsoids, rods, teardrops, dumbbells, and boats. Some of these tektites show contoured, bent and rolled internal structures due to fluid flow while molten. The shapes of splash-form tektites have previously been erroneously associated with aerodynamic shaping. In actuality, these tektites were shaped by variations in rotation rates of partially melted glass droplets. With dumbbell shaped specimens showing the highest rates of rotation and spheroid specimens exhibiting little to no rotation. The size of these “splash-form” tektites is limited by the surface tension of the melt from which they are formed.

Type C

These tektites are type B forms that have been subjected to attack by heat on one side (Called the anterior side), so that a portion of the mass has been lost to ablation and/or has been resculpted to form a flange derived from the anterior side’s material. Often known as flanged “buttons”, these forms are most common in Australites, but are also found in some Javanites.