Amber is a beautiful golden or honey-colored gemstone that forms when tree resin hardens over millions of years. If you've ever seen sap oozing from a pine tree, that sticky golden substance is resin. When ancient trees produced resin, it sometimes trapped insects, leaves, or other small objects inside. Over millions of years underground, the resin fossilized into hard, translucent amber.

Scientists treasure amber because the insects and plants trapped inside are perfectly preserved, like tiny time capsules from prehistoric forests. Some amber contains mosquitoes or flies from the age of dinosaurs, still looking much as they did 100 million years ago. Museums display these amber fossils so we can peer directly into ancient ecosystems.

People also use amber to describe colors. An amber traffic light glows golden-yellow, warning drivers to slow down. Amber eyes have a warm, golden-brown color. When you see something described as amber, picture that warm, glowing honey color that seems to have sunlight trapped inside it.