It's amber, holding the feathery tail of a baby dinosaur who got trapped in tree resin 99 million years ago, along with Cretaceous-era ants. Here is a close-up of the feathers, with a glimpse of an ant:
Now just think about it. You're looking at feathers from a creature that lived almost 100 million years ago. Think about that number. Think about time. Think about those delicate feathers that adorned a baby's tail so long ago that we don't know how to think about it -- but there they are for us to see today, as swirling and graceful and immediate as if the dinosaur had just hatched. Not to mention the ants. Look at those ants! You're seeing the ants and the baby's perfect tail across millions upon millions of years.