Amber is a “gem” that’s often a window into the ancient past.

For thousands of years it’s been valued for its beauty, collected by humans and formed into jewelry and other treasures.

But amber is actually not a gemstone, or a mineral at all. It’s fossilized tree resin.

Trees secrete resin in reaction to damage. The resin hardens like a scab to seal the injury and protect the tree from disease. But while

it’s hardening, it’s extremely sticky and can trap pieces of plants, even small creatures within it.

Many of these are too delicate to be preserved in the fossil record, and are only available to scientists in amber.

Specimens have been found around the world. Amber erodes out of the Baltic seashore, and can be mined in Myanmar, Canada, the Dominican

Republic and many other places.

Collectors and researchers have found flies, spiders eating those flies, and mites clinging to the legs of those spiders. Lizards and

salamanders. Feathers from birds, and from dinosaurs.

Even a nearly entire baby bird, complete enough that researchers could study the structure and color of its skin and feathers -- even the lice that lived on them.

In fact, amber preserves tiny insects and arachnids almost like they’re modern specimens, allowing scientists to examine bugs that went extinct 100 million years ago as if they were alive today.

This makes amber not just a beautiful gem, but a valuable scientific tool.