Tektite Value, Price, and Jewelry Information

Tektite (moldavite), Czech Republic (6.4). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Are Tektites Meteorites?

Scientists have proposed different theories about the origins of tektites. For example, it has been argued that tektites formed from an explosive event on the Moon and were thrown all the way to the Earth’s surface. However, current scientific consensus holds that tektites formed from the impact of meteorites on the Earth’s surface. Material from the Earth, melted on impact, was ejected into the atmosphere, then fell back to the surface and cooled into tektites.

Unlike stony, iron, and stony-iron meteorites recovered on Earth, tektites have terrestrial origins. Although formed by meteorite impacts, the tektites themselves have never been in outer space. The composition of tektites is consistent with terrestrial materials.

Philippinite (rizalite), 3 x 2 x 1 cm, 10 g, Paracale, Camarines Norte, Luzon, Philippines. Photo courtesy of liveauctioneers.com and Jasper52.

Tektite Varieties and Sources

The following table contains information on tektites most likely of interest to gemologists and jewelers.

The refractive indices (RI) of tektites seem to vary (positively) with iron content.

* Lapidaries have faceted this material.

A translucent georgiaite, found in Dodge County, Georgia. Photo by Megan.ruffin1. Licensed under CC By-SA 4.0.

Distinguishing Tektites from Other Glass Varieties

Vendors may sell manufactured glass pieces as natural tektites, particularly moldavites. (Of course, these are the most well-known variety and most likely to appear in jewelry or as cut gems). Examining inclusions and testing for fluorescence are the easiest ways to begin identifying them. See the moldavite gem listing for more information.

Tektites may be confused with another variety of natural glass: obsidian. While tektite is rare, obsidian is very common, which may lead to some misidentifications. This volcanic rock has many properties that overlap with those of tektite: color, hardness, specific gravity, and RI.

Analyzing obsidian and other natural glasses with an Ultraviolet-visible-Near Infra-Red spectroscope (UV-vis-NIR) will show sharp bands at 1380 and 2210–2250 nm, which indicate the presence of water. Tektites won’t have these bands because they contain virtually no water.

This near total absence of water makes possible another, more dramatic, way to distinguish tektites from obsidians. Jim Tobin explains this procedure in his 2003 article on tektite testing. When gently heated with an oxy-acetylene flame, obsidians will froth and become pumice. In contrast, tektites won’t froth. However, after cooling down, they’ll invariably shatter within a few hours due to thermal stress. (Obviously, this test isn’t recommended for finished gems).

Tektite Sizes

Lapidaries have faceted moldavite gems weighing up to 25 cts. Other, more rarely faceted tektites are typically much smaller, although large pieces of rough indochinite and Libyan desert glass have been found.

An unusually large, pear-cut indochinite, 8.4 x 22 x15 mm, 12.75 cts, Laos. Photo courtesy of liveauctioneers.com and Jasper52.

Caring for Tektite Jewelry

Tektites range in hardness from 5 to 6.5, which makes them susceptible to scratching. (Household dust, with a hardness of 7, would easily scratch their surfaces). As ring stones, they should receive protective settings and only occasional wear. However, other jewelry uses, such pendants and earrings, should present no problems.

Since tektites can contain numerous inclusions, don’t use steam or ultrasonic systems to clean them. Instead, use a soft brush, mild detergent, and warm water. Consult our gemstone jewelry cleaning guide for more recommendations.

Tektites: Libyan desert glass, Libya (4.12); Moldavite, Czech Republic (6.05). Photo © Joel E. Arem, PhD, FGA. Used with permission.