Definition and Formation

Source: Les secrets de l'amber dominicaine

Amber is a hardened tree resin, composed of alcohols, compounds of terpenes, and esters. Trees produced it as a protection against disease and insect infestation when the bark of a tree was opened due to a limb that had broken away, attacks by wood-boring beetles, or for other reasons. After oozing out, it hardened in wet sediments, such as clay and sand that formed at the bottom of lagoons or river deltas and was preserved in the earth's crust for millenniums.

The chemical composition of the resin acted as desiccant and antibiotic, which caused that animals like insects and non-insects - i.e. mosquitoes, flies, spiders, ants and their eggs and emerging larvae - and even lizards and frogs, when caught in the resin, became entrapped and preserved as dehydrated fossil inclusions, but without the shrinking effect dehydration usually causes. They were kept in such a way that their cellular structure and even fragments of the DNA could still be found today.