How amber creates exquisite fossils that preserve Earth's history

Warm-colored amber samples act as a 3-dimensional window to help scientists recreate ancient ecosystems through the countless animal and plant entities they contain.

Accumulated over tens of millions of years, fossilized tree resin, known as amber , has fascinated jewelry makers and inspired scientific research.

 The resin secreted by coniferous trees over millions of years can turn into amber. (Photo: ICA)

For the past 200 years, paleontologists around the world have used amber to learn about the ancient past by studying the ancient fossils preserved within it.

How amber is formed

Amber is essentially ancient conifer resin , a warm-toned liquid that flows from trees that are diseased or have holes in their trunks.

This is a complex, sticky substance that is insoluble in water and hardens when exposed to air to form a protective cover on the plant's wound, helping to ward off fungi and other pathogens.

Because sap is sticky, small creatures can get stuck in it when the sap oozes on tree bark, drips to the ground, falls into water, and then these sap drops are buried in place or washed away into rivers. , sea.

Over time buried in sediment, drops of tree sap under the influence of pressure and temperature will undergo countless changes and transformations to 'mature' , becoming a dense layer of molecular bonds. , hard as rock and clear as glass that we call amber, and it can also preserve the form of any creature trapped within it with incredible structural integrity. surprised.

Amber is found in 7 main colors and 300 different color zones. The most popular is still orange-yellow, almost honey-colored. More rare are red, green and especially rare blue amber.

Only about 10% of amber is transparent, the remaining 90% is opaque. These different colors are determined by the natural source of fossilized tree resin and the impurities inside.

The oldest amber on Earth - found in the Illinois coal seam in the US - is dated to be about 320 million years old, long before the dinosaurs appeared.

However, these blocks of amber average less than a quarter of an inch wide, and they do not contain any fossils inside.

According to the International Colored Gem Association (ICA), amber must be at least 40,000 years old , and the Gemological Institute of America (GIA) believes that it takes 1 million years for tree sap to turn into amber.

 Amber containing inclusions of the crab Cretapsara athanata 100 million years ago was discovered in Myanmar. (Photo: LIDA XING)

Specific information is still being researched by scientists, but all agree that it takes at least 40,000 years for a fossil resin sample to become amber.

If younger than that, the material is more likely to be classified as copal – a 'young' fossilized tree resin that has some of the properties of the new material, such as a stickier surface.

Amber in the world

Amber and copal are found in 160 locations worldwide, but only a few dozen places have amber containing fossil inclusions inside.

Most of these fossil deposits are around 125 million years old or younger, with the exception of a 230 million-year-old amber mine in the Italian Alps, which preserves an ancient fly and two mite species.

Any plant or animal species can be partially or completely 'preserved' by amber , from flowers, leaves, insects to vertebrates that live around the environment of trees that secrete resin to create Amber.

Warm-colored amber samples have acted as a three-dimensional window to help scientists reconstruct ancient ecosystems through the countless animal and plant organisms they contain.

For nearly two centuries, paleontologists studying amber have found about 1,300 types of plants and animals, including extinct species, from lizards, insects, spiders, crabs, to leaves. , flowers, fungi, microorganisms, feathers and other plant debris.

Currently in the world there are 4 famous amber mines that are the most researched.

Baltic amber

The Baltic regions are home to the largest known deposits of amber, known as Baltic amber or golden amber. It has been estimated that the forests have produced over 100,000 tons of amber.

They are 34-38 million years old and contain more than 3,500 species of fossil arthropods, including more than 650 species of spiders.

 Baltic amber containing the gecko Yantarogekko balticus has been dated to be about 54 million years old. (Photo: WOLFGANG WEITSCHAT)

It is rare for Baltic amber to contain vertebrates, but a piece of amber has been discovered containing the inclusion of a Yantarogekko balticus gecko dated to about 54 million years old.

In addition, scientists also discovered in Baltic amber the largest flower fossil ever found.

Dominican Amber

Dominican amber differs from Baltic amber in being nearly transparent and having a higher number of fossil impurities. This has allowed for a detailed reconstruction of the ecology of a long-lost tropical forest.

In addition to the common yellow and honey colors, Dominican amber also comes in smaller quantities in red and green, especially the rare (fluorescent) blue.

Dominican amber is believed to be 15-20 million years old although the exact age is still a matter of debate.

Scientists have found more than 1,000 species of fossil creatures in amber here, including more than 400 species of insects and 150 species of spiders. Sometimes fossil inclusions of vertebrates, including salamanders, appear.

Myanmar Amber

Myanmar amber is about 99 million years old, mined from mines in Kachin province, northern Myanmar - which has mined and provided gems for the jewelry industry for the past 2,000 years.

 A juvenile tick clings to a dinosaur feather preserved in a 99-million-year-old piece of Myanmar amber. (Photo: National Geographic)

Over the past two decades, interest in Myanmar amber has increased as paleontologists have discovered the incredibly diverse biota found in the amber here. These are amber containing a carnivorous ant that 'froze' mid-meal; part of the tail of a feathered dinosaur; the shell of a sea creature called an ammonite, and even an ancient baby bird.

Canadian Amber

Canadian amber is 78-79 million years old, mainly discovered in the Grassy Lake area of ​​Alberta province in Western Canada.

Scientists found more than 130 different fossils in the amber here, many of which were mites or aphids. Some other amber samples also contain pieces of needles, mushrooms, pollen, and even bird or dinosaur feathers.

By preserving organisms intact for tens of millions of years without being affected by physical and chemical agents of the environment, amber has helped preserve a part of Earth's history. David Federmand, author of a book on gemstones, says: 'Amber is like a time capsule created by Mother Nature and placed on this Earth' .