Cicada Fossil Trapped in Opal Opens New Window on Ancient Life—and Mars

The mosquito trapped in amber has had a long run as the fossil world's most glamorous prisoner—ever since it starred in Jurassic Park, suspended in Dr. Hammond's cane, a tiny time capsule that supposedly held the genetic secrets to resurrecting dinosaurs. But a new discovery suggests that amber has never been the only stone capable of holding ancient life in perfect suspension. A cicada shell, pulled from rock in Indonesia, has been found encased in opal, preserved so completely that it looks, as one researcher noted, like something deep-fried and mounted for display. The specimen has been nicknamed Beverly, and it opens a door that researchers are only beginning to walk through.

Opal forms under conditions far gentler than most people realize. It crystallizes at relatively low temperatures in the cracks and cavities of rock—sandstone, basalt, rhyolite, and others—as silica-rich fluids seep through and harden over time. The stone can be transparent or opaque, nearly any color imaginable, though black opal commands the highest prices and white, gray, and green are most common. What makes Beverly remarkable is not just that it contains a fossil, but how that fossil came to be there in the first place.

The cicada shell's journey into stone began with volcanic activity. As volcanic rock and glass weathered away, they released silica into groundwater. This silica-laden fluid filtered slowly through the surrounding rock, carrying with it the dissolved minerals that would eventually become opal. The cicada shell, likely deposited in a clay layer formed from decomposed plant material, sat in the path of this creeping mineralization. As the fluid moved past, a silica-rich mineral called zeolite crystallized directly onto the shell's surface, coating it in a protective layer. Over time, more silica accumulated, and the opal formed around the preserved insect, sealing it away from the world for millions of years.

The result is a clear stone that holds the cicada in perfect detail, a window into a moment of deep time. But Beverly's significance extends far beyond the simple fact of its preservation. Early Earth was a volcanic world, the kind of place where opals could form readily. And here is where the story turns toward the sky: early Mars was also volcanically active. The Red Planet's ancient surface, before it lost its magnetic field and most of its atmosphere, would have provided the same conditions that created Beverly—weathering rock, silica-rich fluids, the slow accumulation of minerals in stone.

This realization has shifted how scientists think about searching for ancient life beyond Earth. If opal can preserve organisms here, it might do the same on Mars. Future rovers and missions to the Red Planet could be tasked not just with looking for fossils in obvious places, but with hunting for opals in ancient volcanic regions—stones that might hold the remains of microbial life or other organisms that once inhabited the Martian surface. The search for extraterrestrial life, in other words, might soon involve the same kind of patient, careful examination that paleontologists have always used on Earth, only applied to alien stone. Beverly, a cicada shell in a precious gem from Indonesia, has become a kind of proof of concept for an entirely new way of looking for life among the stars.