THE’amber It is a substance natural of origin organic of glassy, formed through thehardening and the fossilization from the vegetable resins which ran along the trunks of the trees in past geological eras. It is therefore not a mineral in the strict sense of the term. For millennia, Ambra has aroused human interest, finding employment in the realization of jewels and everyday objects, but also considered a mystical substance used in numerous religious rites. For i geologists he is paleontologistsAmbra is one of the main windows on the ecosystems of the past, since it can preserve, inside, fossils Of small animals vertebrates, insects, hair, feather And remains vegetablesall perfectly preserved. In contemporary culture, this characteristic of amber has become central to the creation of dinosaurs in the famous film Jurassic Park – Although, it is good to reiterate it, it is pure science fiction.
What is fossil amber and how it is formed
THE’amber is one resin fossil solidified that thousands or millions of years ago has been formed and that has been preserved within the rocks sedimentary up to the present day. The resin they are substances viscous and sticky to secrete from some types of plants, in particular from those woody like the coniferin order to heal wounds, playing a role completely similar to that of platelets in ours blood. When the resin comes out of an injury, like one crack In the bark of a tree, yes harden to contact with the air and cause of exposure to sunlight, forming a coverage rigid which protects the plant from mushrooms and other pathogens.
Due to the action of agents exogenouslike the wind and rain, the resin can be transported far away From its point of origin and buried in the sediments of the bottom of a lake, in the alluvial plains or in the seabed. With the passage of time, these sediments are subjected to temperatures And pressure hightriggering chemical and physical reactionsdefined as the name of diagenesis or diagenetic processes that, in the long run, transform the resin into fossil amberpreserving it up to the present day.
The time necessary for a resin to become amber is not constant, but it can vary from hundreds of thousands to millions of years. This interval depends on numerous factors, including the time required for the solidification of the resin, its transport, and the duration and intensity of the diagenetic processes. The resins not completely fossilized, or i semi-phossilare called cig. These are substances tendentially youngerwho have just started the process of fossilization or “ambiorization”, and are generally softer and more opaque than the completely fossilized ambra.
Characteristics of the Ambre
The deriving plagues are mainly composed of carbon, hydrogen And oxygenwith traces of sulfur. They are relatively not very dense and can vary in color, ranging from tones yellow And orange pale to the darker ones of red And brown. The coloring depends on various factors, such as the type of tree on which the resin comes, the presence impurities and the duration of the fossilization process.
Amber has a very low specific gravity and a hardness between 2 And 2.5 on the Mohs scale. In addition, it often contains numerous microscopic air bubbles that give it the ability to float, thus facilitating their transport through rivers or seas.
Ambra, a very ancient fossil resin: what hides inside
Since the vegetable resin is viscoussmall organisms can be trapped while dripping on the cortex of trees, drips to the ground or comes out of the roots. The Amber, in fact, have been one of the main sources of insects fossils perfectly preserved. A famous example in the cinematographic world are the mosquitoise found in the ambraus of Jurassic Parkused in the film to extract the DNA of the Dinosaurs.
However, scientists also discovered numerous other trapped animals, including lizard, frogs, Salamandrebeyond fragments leather, hair of animals and feather. The degree of conservation of these fossils inside the Ambre is among the best in the world, since the remains, surrounded by the resin, are quickly subtracted from the natural processes of degradation And necrolysispreserving them in an extraordinary way.
The best known fossil plates
Exist beyond 200 sites In the world where fossil ambres were found. Among these, the oldest planes, dating back to the period Carboniferous (about 320 millions years ago), they were discovered in coal deposits in theIllinois, in the United States of America. These are small gems that, however, do not contain fossils. In fact, only some deposits are particularly rich in ambre containing fossils. In Italyin DolomitesAmbre containing a kind of fly and two species of mitesabout about 230 millions years ago. These are Ambre older Never found with insects inside them.
The most well -known and common type of amber is that Balticcoming from the sediments of the Seti (ancient between 56-34 million years) present along the coasts of Baltic Sea. Inside the Baltic Air were discovered beyond 3500 species of arthropodsincluding hundreds of species of spiders. Another well known variant is theamber Dominicanwith an estimated age between 15 he is 20 millions Of yearswhich has returned beyond 400 species Of insects And small vertebratesincluding Salamandre.
THE‘amber Burmesedating back to Cretaceous superior (about 99 million years ago), comes from the mines in the state of Kachinin the north of Myanmar. These Amber testify to a Extremely diversified ecosysteminside which remains of ants predatorsfragments of dinosaurs feathered, warning and even a flea.
Another important location for the extraction of fossil is Grassy Lakein Alberta, Canada. THE’amber Canadianwith an age between the 77 he is 79 million yearshas returned numerous species of aphids, needles coniferous, mushrooms, pollen and also feather of dinosaurs and other birds. In Italy, one of the best known deposits is found in Sicilyin the province of Caltanissettaexposed by the action of the Simeto river. This amber, called Emphis from Pliocene-Milan age and is famous for his color red dark transparent, but can also present blue shade or green.
Use of Ambra
The archaeological record suggests a wide range of users of fossil amber, ranging from links with magical cults and practices, such as the realization of amuletsto the creation of simple Daily tools, knives, toys And objects decorative. Obviously, there were also the uses of ambra for the creation of jewelsstill highly appreciated today, or for the realization of lenses. Also, Ambra burnt as incense It had a significant role in religious rituals, both before and after the classic era.
