Have you ever heard of amber? Amber is a translucent gemstone that is used in jewelry. But do you know where amber comes from?
Amber is fossilized tree resin! Some trees (especially coniferous trees such as pine trees and redwoods) produce a thick, sticky substance that oozes out of breaks and cracks in its wood. This sticky substance is called resin. Scientists are still arguing about why trees make resin. Some scientists think that trees make resin to protect themselves against bugs and other things.
Other scientists say that trees just make resin by accident. Who knows? Maybe someday YOU will figure it out! Here is a picture of resin dripping from a pine tree:
From Wikipedia Commons
When resin gets buried underground, it can turn into a fossil. Over a long period of time (scientists think tens of millions of years) resin that is very far underground experiences very high temperatures and pressures. The very high temperatures and pressures “boil off” some of the chemicals in the resin and cause others to polymerize. This means that the smaller molecules link up like train cars in a train. Over time, this polymerization forms amber.
Because amber started out as a thick, sticky liquid, it sometimes contains things trapped inside, like pieces of plants, rock, or even bugs! Here is a picture of a spider that was trapped in an amber gemstone.
from Wikimedia commons, uploaded by Elisabeth from the Netherlands
Amber comes in different colors, ranging from white to pale yellow to brownish-black. Amber of other colors has also been found, such as red, green, or even blue (although blue amber is very rare and very expensive.) Most amber is a golden color, sort of like honey. This is the color people mean when they say something is “amber-colored.” Amber can be melted and burned, and in the past people used to use it as medicine or in perfume.
Amber was important in our understanding of electricity. As far back as 600 BC, a philosopher from ancient Greece (Thales of Miletus) noted that rubbing fur on amber made the amber attract light objects, like hair. Later, scientists discovered that the fur was leaving electrons behind on the amber, giving the amber a slight negative charge. In fact, the words “electron” and “electricity” actually come from the Greek word for amber!
Amber was recently in the news. Scientists excavating amber in western India found many pieces of amber with ancient insects, arachnids, crustaceans, plants, and even mammal remains trapped inside. The scientists think that the specimens are about 50 million years old. Because some of the fossil insects are similar to fossils found in Central America, this amber might change what geologists think the arrangement of continents in the ancient world may have been.
Spider found in the Cambay amber deposit of western India. (Photo by David Grimaldi/AMNH)
From electricity to insects to ancient geography, amber is amazing—just like you!