Turns Out Insects Can Be Trapped In Opals, Not Just Amber

Remember how in the original Jurassic Park, the scientists are able to obtain dinosaur blood from prehistoric mosquitoes trapped in amber? Amber fossils are one of the only true aspects of the movie. Millions of years ago, bugs would get trapped in liquid tree resin, which over time, hardened into amber. Researchers find amber fossils with all sorts of critters often engaged in battle one another, like the fossil found in 2012 featuring a spider attacking a wasp. Since only amber-trapped insects have been found, it was believed this was the only type of fossil gem. However, a recent discovery contradicts this theory.

An ant trapped in amber (photo by Anders L. Damgaard)

Gemologist Brian Berger bought an opal from Java, Indonesia. As expected, the stone was beautiful and multi-colored. As he looked closer, he saw an insect perfectly preserved inside. How did this happen?

How opals are formed is somewhat mysterious to scientists and gemologists. The most popular theory is that water full of silica (a compound that also makes up most of sand) pours over sediment, filling various holes and cracks. When the water evaporates, the silica deposits stay back. Over time, as more silica-water passes by and then evaporates, an opal forms. In Indonesia, where the bug opal in question came from, volcanic fluid is added to the mix.  

For this particular opal, however, the process might have been longer. It could be that the bug was trapped in tree resin, which turned to amber, and then that amber eventually transformed into an opal. If that ends up being the case, the insect could (in theory) be the oldest ever found.

Did the opal fossil begin as tree resin, then turn to amber, and then to an opal?

For now, the bug prisoner’s story remains a mystery. We do know the sample is legit; Berger sent it to the Gemological Institute of America, which said the stone is indeed an “unaltered, untampered precious opal” with a “genuine” bug trapped inside. Berger plans on finding a paleontologist or entomologist who can help him learn more.


Amber photo credit