Selling elephant ivory—a hard white material from elephant tusks, for which elephants are often killed—is illegal. Selling ivory collected from the remains of extinct Mammoths, however, is—somehow—not. Because the two are hard to tell apart, illegal traders are slipping under the radar by mixing elephant ivory with legally traded mammoth ivory. A new forensic tool, however, might soon put an end to this nefarious trick.

Wildlife forensic scientists in China suggest that authorities can differentiate elephant ivory from mammoth ivory by analyzing stable isotopes (forms of an element that don’t break down over time). If this approach becomes widely adopted, it could serve as a quick sample screening before the application of more expensive and time-consuming methods.

“Mammoth ivory costs a fraction of the price of elephant ivory, but the two are considered completely different materials by carvers and experts, because mammoth ivory usually lacks the deep, creamy white color of elephant ivory,” Pavel Toropov, a University of Hong Kong researcher and a co-author of the study published today in the journal Frontiers, said in a Frontiers statement. “One trader compared them to a ‘Lamborghini and a Ford.’ Mammoth ivory cannot be a real substitute for elephant ivory, but its value may lie in providing a legal cover for elephant ivory.”

Currently, the most accurate way to tell the two ivories apart is via molecular analysis (studying molecules) or radiocarbon dating (a technique to date organic material), both of which are expensive and time consuming.

Isotope ratios vary depending on factors like environment. Since Ice Age mammoths preserved in high-latitude Siberian permafrost lived in a completely different habitat from today’s tropical elephants, the isotope ratios in their tusks should be different. Within this context, Toropov and his team decided to investigate whether analyzing these differences could provide a better method to distinguish between the two types of ivory.

The team conducted stable isotope analyses on 44 pieces of elephant ivory and 35 pieces of mammoth ivory, specifically studying the stable isotope ratios of carbon, hydrogen, nitrogen, oxygen, and sulfur. While this approach revealed notable overlap for carbon, nitrogen, and sulfur isotope ratios between the two ivories, the researchers documented very little overlap in the elephant and mammoth isotope ratios for oxygen and none for hydrogen.

“This is because the elements of water drunk by mammoths in high-latitude regions such as Siberia have distinct isotope signatures compared to the elements of the water ingested by elephants in tropical latitudes,” explained first author Maria Santos, also a researcher from the University of Hong Kong. Simply put, analyzing the stable isotope ratios of oxygen and hydrogen in a suspected ivory object is an effective way to determine whether it came from an elephant or a mammoth.

While more research is needed before this approach can be used in a court case, “we hope that the protocol described in our study will be applied to screen large batches of supposedly mammoth ivory objects,” Santos added. “Samples that have an isotopic signature of elephant ivory can then be tested with more expensive and time-consuming methods, such as radiocarbon dating. This could help combat the illegal ivory trade more effectively and close the potential laundering loophole.”

The way I see it, there’s an even simpler solution: Make all ivory illegal.