Tektite

Start with the surface texture, because it is the most reliable clue. Genuine tektites carry a busy, natural sculpture of pits, grooves, dimples and U-shaped gouges, and many show smooth, aerodynamic shapes — rounded buttons, teardrops, dumbbells and discs — that record their molten flight through the air. The body is a dark glass: hold it to a strong light and most tektites glow brown along thin edges, while green moldavite is clearly translucent. The material is true glass, so it has a conchoidal (shell-like, curved) fracture, a glassy to slightly greasy luster, and a white streak, and it is only moderately hard at about 5 to 6 on the Mohs scale.

Weight and magnetism help rule out impostors. A tektite feels noticeably lighter than a piece of metallic iron meteorite of the same size and is essentially non-magnetic, which immediately separates it from the iron meteorites it is sometimes confused with. Despite the cosmic origin story, remember the key identification fact: a tektite is melted Earth rock, not the meteorite, so it will not show the metal flakes, fusion crust or strong magnetism of an actual stony-iron or iron meteorite. If you have a dark, lightweight, non-magnetic natural glass covered in irregular pits and gouges — and it is not the suspiciously perfect, bubble-filled glass described in the fakes section — a tektite is a strong candidate.

The great majority of tektites are black to very dark brown, looking jet-black in reflected light but revealing a smoky brown glow when a thin edge is held to the sun. These dark tektites are grouped and named by the strewn field — the broad region across which a single impact scattered them. Indochinites from Southeast Asia, australites from Australia, bediasites from Texas and georgiaites from Georgia are all essentially this dark glass, distinguished mainly by where they fell and by characteristic shapes (Australian australites, for instance, are famous for button and lens forms with flanges).

The standout exception in color is moldavite, the translucent bottle-green to olive-green tektite found chiefly in the Czech Republic and tied to the impact that formed the Ries crater in Germany. Its forest-green transparency and delicately etched, wrinkled surface make it the only tektite routinely cut and set as a gemstone, and it commands prices far above ordinary black tektites. A few other localities yield greenish or yellow-green glass, but for practical purposes the color story is simple: most tektites are dark, and green essentially means moldavite.

In modern crystal-working and metaphysical traditions, tektites are prized precisely for their dramatic origin — glass forged in a collision between Earth and sky. People describe them as stones of transformation and high-frequency energy, associated with expanded awareness, spiritual growth and a connection between the earthly and the cosmic; moldavite in particular has a near-cult following as an intense, fast-acting stone of change. These associations draw directly from the impact-born story rather than from any chemical property of the glass.

These meanings are cultural and spiritual, not scientifically established medical effects. A tektite is a remarkable natural object to study and collect, but it is not a treatment for any physical or emotional health condition and should never replace advice or care from a qualified medical professional. Enjoy a tektite for the extraordinary geological event it records and for its strange beauty, not as medicine.

Value among tektites is sharply divided by type. Common dark tektites — Indochinites, australites and similar strewn-field material — are relatively affordable and widely available, with price driven by size, an interesting or complete aerodynamic shape (buttons, teardrops and flanged forms fetch more), undamaged surfaces, and provenance from a documented locality. Most ordinary black tektites are inexpensive natural curiosities rather than precious stones.

Moldavite is the dramatic exception. As the only gem-quality tektite, with a limited Czech source and rising demand, faceted and high-grade moldavite sells for far more than dark tektites, and clean, deeply etched, richly green pieces command a premium. That value gap is exactly why moldavite is so heavily faked (see below), so for moldavite especially, value tracks honest identity: pay gem prices only for material whose authenticity and source you trust. As always, an honest identification should come before any discussion of price.

The most common fake is manufactured glass — including ordinary green bottle glass, art glass and industrial slag glass — passed off as tektite or, more lucratively, as moldavite. Tell-tale signs of fakes are too-perfect, blobby or molded shapes, a smooth or merely frosted surface instead of natural pitting, and especially round internal gas bubbles: tektites can contain elongated or sparse bubbles, but neat spherical bubbles in abundance point to melted manufactured glass. Faked moldavite is often an unnaturally bright, uniform emerald-green with a glossy, freshly molded surface, whereas real moldavite shows a more muted forest-to-olive green and a finely wrinkled, etched skin that is hard to counterfeit. Mold seams, a glassy ring when tapped, and a color that is suspiciously even are all warning flags.

Two honest mix-ups, rather than deliberate fakes, also catch people out. Obsidian, a volcanic glass, can look like a black tektite, but it forms from lava at a volcano rather than from an impact, lacks the gouged aerodynamic shapes, and tends to occur in larger, smoother masses. Iron and stony-iron meteorites are sometimes confused with tektites because of the shared space association, but they are heavy, strongly magnetic and metallic — the opposite of a tektite's light, non-magnetic glass — and recalling that a tektite is melted Earth, not the meteorite, resolves the confusion. When buying valuable moldavite, favor sellers who guarantee authenticity and, ideally, provide locality information.

Tektites are glass, so the main hazards are chipping and scratching rather than chemical attack. At about 5 to 6 on the Mohs scale they are softer than quartz and can be scratched by harder stones, and like all glass they have a brittle, conchoidal fracture, so a sharp knock can chip an edge or shatter a thin piece. Store tektites separately, padded away from harder gems and from each other, and handle delicately etched moldavite especially gently, as its fine surface sculpture is part of its value and is easily worn or marred.

Cleaning is simple: use warm water, a drop of mild soap and a soft brush or cloth, then rinse and dry. Avoid harsh chemicals and prolonged soaking, and skip ultrasonic and steam cleaners, which can stress the brittle glass and may worsen any hidden fractures. Kept away from impacts and abrasive surfaces, a tektite needs little maintenance and will hold its strange, deep-space-born appearance indefinitely.