The Mini Museum Library - Articles, Essays, Specimen Deep Dives, and Current Research

A Dinosaur with Golden Bones?

December 7, 2022

An artistic rendering of an Iguanodon.

If you’ve ever seen a dinosaur’s skeleton in a natural history museum, what you’ve seen is a stone replacement of the original dinosaur’s bones. Sometimes, a mineral will leach into the bones' pores during permineralization, preserving the bones and infusing them with outside elements, as in the Bernissart Iguanodons. These impressive specimens have been pyritized, sparkling as though they're made of gold.

In 1878, Belgian coal miners in Sainte-Barbe found a massive pocket of clay hundreds of meters below ground. Inside the pocket, what the miners thought was gold wedged in tree trunks was really thirty intact Iguanodons, all of them pyritized.

Pyrite, better known as fool’s gold, is an iron-sulfur compound that while worth little is a beautiful mineral. To the miners, it looked as though they had come across thirty Iguanodons with golden bones. They formed when algae in swampland reacted with iron sediment, creating pyrite that poured into the remains of the dinosaurs.

The thirty Iguanodons (and a host of other discovered creatures) were carted off to the Belgian Royal Museum of Natural History where they were studied and later set up for display. Originally the specimens were arranged in a bipedal position, in what was then believed to be the animals’ natural walking posture. Later in 1980 on these same fossils it was determined that Iguanodons moved about on four legs. They can still be seen on display today, though the remains are too fragile to rearrange into their correct stance.

Want to learn more about the Iguanodon and even get a pyritized piece of your own? Check out our Pyritized Iguanodon specimen in the shop!