By Adam Kelliher
The short answer: most fake fossils can be caught with a 10x loupe and good light. Look for tiny air bubbles (a sign of cast resin), a colour or texture break between the fossil and the rock around it, glue seams, and too-perfect detail. A UV light and a careful scratch test can help, but neither proves anything alone.[1][2]
Fossils are old, rare and sometimes expensive, which makes them worth faking. Trilobites are a favourite target. The good news is that most fakes give themselves away if you know where to look.
Restored, composite or fake?
- Restored: a real fossil with small repairs, like a filled crack or a replaced spine tip. Common, and fine if the seller tells you.[2]
- Composite: parts of different real fossils put together as one, sometimes called a "Frankenstein".[1]
- Fake: a cast, carving or resin model sold as a real fossil.[2]
Casts aren't bad in themselves. Museums use them all the time, as long as they're labelled as casts.[3] The problem is selling one as the real thing.
1. Bubbles
Resin traps air as it sets. Tiny round pits, usually under half a millimetre, in the fossil or the rock around it point to a cast.[2]
2. Colour and texture breaks
Natural preservation is fairly even across one specimen. A part that's a different colour, a sudden change in texture, or a thin line where two pieces meet suggests joined or added parts.[1][2] Turn the piece over. If the back of the rock doesn't match the front, ask questions.[2]
3. Surface and shine
Resin trilobites often have an odd, shiny look, and the colour can be off from what that locality normally produces.[2] Real detail, such as eye lenses on trilobites, is hard to fake well. Wax and glue also look and reflect differently from real bone or shell under magnification.[1]
4. Hardness
Real fossils are mineralised and hard. Wax and glue are softer, so careful pressure with a needle in an inconspicuous spot can show a difference.[1] Some collectors use a heated needle: it sinks into resin but not into a real trilobite.[4] Only do this on something you own, and on a hidden spot.
5. UV light
Many glues, waxes and resins glow differently from rock under UV, and real bone from different sources can glow differently too.[1][2] But some resins don't glow, and waxed or finished real fossils can.[2][5] Treat UV as a pointer, not a verdict. Here's how to use a UV light.
6. Common sense
A perfect, complete specimen at a bargain price is the oldest red flag there is. Complete fossils are rare, and that rarity is exactly why people fake them.[1] Buy from someone who will tell you what's been restored. Learn more about fossil types in body fossils, trace fossils and casts, and browse all our fossils or statement fossils.
See what's new: browse our newest arrivals for the latest pieces added to the shop.
Sources
- Mateus, Overbeeke and Rita (2008), Journal of Paleontological Techniques: Dinosaur Frauds, Hoaxes and "Frankensteins": How to Distinguish Fake and Genuine Vertebrate Fossils.
- Trilobites.info: Tutorial, How to Identify Fake Trilobites.
- Museums Victoria: Know Your Bones: What Is a "Real" Fossil?
- The Fossil Forum: collector discussion of the hot-needle test on trilobites.
- The Fossil Forum: collector discussion on using UV to detect restorations.