Natural Impact Glass vs Nuclear Bomb Glass

Updated 5 November 2026 · Standard formula, shown below

This guide helps you compare suspected natural impact glass with glass formed by a nuclear explosion, using context and observable features rather than a single supposed giveaway. You will need a clear photograph, basic protective equipment, and any reliable information about where the specimen was found; definitive identification usually requires a qualified laboratory.

What You’ll Need

Safety glasses and disposable nitrile gloves
A hand lens or magnifier and a ruler for scale
A camera or phone, plus a notebook for observations
Known location and collection details, if available
A sealed, sturdy container for transport; do not break, grind, or wash the specimen

Step-by-Step

Handle it as an unknown material. Put on gloves and avoid rubbing, scraping, or sniffing the specimen. Glass can have sharp edges, and an unknown sample should not be treated as safe merely because it looks like ordinary glass. Do not use a Geiger counter result or lack of one as proof of origin.
Record the find before interpreting it. Note the exact location as accurately as possible, date, depth or surface position, and whether it came from a documented collection or disturbed fill. Photograph it in place if possible, then photograph all sides with a ruler. Keep the original context: geographic setting is often more useful than appearance.
Check whether the location fits a known natural impact field. Natural impact glass can form when a meteorite impact melts and ejects local rock. Examples include tektites found in geographically defined strewn fields and glass associated with particular impact structures. Compare the find location with published geological maps, museum references, or a university geology department. A specimen found far outside a documented field is not automatically artificial, but it needs a stronger explanation.
Consider whether the site fits a nuclear-test context. Nuclear explosion glass is usually associated with a known detonation site or fallout area, and its composition reflects local soil, sand, or building materials melted by intense heat. Check credible historical and geological records for the area. Do not enter restricted, contaminated, or unsafe sites to collect samples. A glassy object from a general desert or industrial area is not enough to establish a nuclear origin.
Describe visible features without treating them as a verdict. Record color, transparency, bubbles, flow-like textures, inclusions, and whether the surface is pitted or weathered. Some tektites are dark, aerodynamic-looking, and internally bubble-poor; other impact glasses can contain abundant mineral fragments and bubbles. Nuclear-test glass may be irregular, vesicular, or fused with soil and debris. These tendencies overlap, weathering changes surfaces, and man-made furnace slag can resemble both.
Look for associated material and documented provenance. A specimen collected with mapped impact ejecta, distinctive impact minerals, or other well-documented material may support a natural-impact interpretation. Glass fused with local sand, masonry, or debris near a documented test site may support an artificial high-temperature origin. Neither association proves the cause by itself; contamination, later fires, and landscaping can mix materials.
Do not perform destructive home tests. Avoid acid, heat, flame, cutting, polishing, crushing, or attempts to test radioactivity by handling or opening anything. Color, magnetism, hardness, and density are not reliable stand-alone discriminators. Even a laboratory measurement only helps when interpreted alongside location and geological evidence.
Ask a specialist for a defensible identification. Contact a geological museum, university earth-science department, or a laboratory experienced with impact materials. Send photographs and provenance first, and ask before shipping. Specialists may examine thin sections and use microscopy or chemical analysis to compare the glass with local rocks and known materials. If the sample is suspected to come from a nuclear site, state that clearly and request safe handling guidance before moving it.

Common Mistakes

Calling any green or black glass “nuclear glass” or “tektite.” Color is affected by chemistry, inclusions, thickness, and weathering; industrial slag, wildfire products, and ordinary melted material can look similar.

Using shape as proof. Rounded, stretched, or splash-like forms can arise in different high-temperature processes. A dramatic shape does not establish a meteorite impact or nuclear event.

Assuming radiation settles the question. A non-detect does not rule out nuclear-test glass, and a reading alone does not identify the source. Natural rocks and unrelated contamination can also contain radioactive elements. Do not interpret a casual instrument reading as a provenance test.

Ignoring where it came from. A laboratory can characterize composition, but without trustworthy location and collection history it may not be possible to distinguish competing origins confidently.

Cleaning or breaking it first. Washing may remove adhering material that helps identify the setting; cutting or grinding can create sharp fragments and dust and permanently alter evidence.

Tips

Keep the specimen separate from other rocks, label the container with the find location and date, and preserve notes and original photographs.
Use neutral descriptions such as “dark glass with bubbles” rather than labeling it “bomb glass” before assessment.
Compare location information with geological publications, not only marketplace listings or image searches.
If you are documenting a collection, distinguish confirmed identification from a tentative resemblance and note who made the identification.

Troubleshooting

You do not know the find location: Record what is known and say what is uncertain. Ask the previous owner for collection notes, labels, or photographs. Without provenance, visual identification may remain inconclusive.

The specimen resembles both types: That is common. Photograph it from several angles, describe the features, and seek expert comparison. Do not select the origin that seems most dramatic.

You cannot find a specialist nearby: Start with a university geology department, natural-history museum, or geological survey contact page. Send images and a short provenance summary before mailing anything; many institutions cannot accept unsolicited specimens.

You suspect it came from a nuclear test area: Stop handling it, keep other people away, and do not collect additional material or transport it casually. Contact the relevant site or public-safety authority for location-specific instructions. If anyone is injured by a sharp edge, use ordinary first aid and seek appropriate care.

Online sources disagree: Give greater weight to peer-reviewed geological work, museum collections, and mapped field data. Ask what evidence supports the label and whether the identification is based on analysis or appearance alone.

Frequently Asked Questions

Can I identify nuclear-test glass by its color?
No. Color varies widely and overlaps with natural impact glass, slag, and other melted materials.

Does nuclear glass always contain radioactive material?
No. Radioactivity is not a reliable yes-or-no identification test, and an instrument reading cannot establish origin.

Are all tektites made by meteorite impacts?
Tektites are generally understood as natural impact-produced glass, but not every glassy rock or droplet is a tektite. Location and scientific examination matter.

Can a photo identify the specimen?
A photo can help screen possibilities, especially with a scale and location details, but it rarely proves the origin.

Should I take it to a laboratory?
Yes, if identification matters. Contact the lab first, share provenance, and ask how to package it safely. Chemical analysis is most useful when paired with geological context.

Is it safe to keep?
Do not assume so from appearance. Minimize handling, keep it contained, and seek qualified advice if its origin or condition raises a safety concern.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.