Natural forms in which amber has often survived testify to its origin equally well as chemical analyses, since forms like that are seen today on tree trunks or branches in forests. Apart from drops and stalactites of all kinds, created by resin exudation, other lumps that have been found are not accidental in their form either. The shapes of the biggest lumps, considered to be special natural phenomena, as well as of the tiny ones allow us to determine the kind of cracks in which once resin collected in a resin-producing tree. Resin healed any kind of external scars, cracks in the bark and underneath it as well as in wood itself. It could also accumulate in so-called resin pockets, or small cracks between annual rings. The inner surface or cracks left imprints of various shapes on the outer surface of amber lumps. As they were created by filling the cracks of differing shapes with originally liquid resin. Thus, the variety of amber forms may be as wide as the multitude of crack shapes in tree trunks and branches. Lumps of amber are comparable to fossil forms known as moulds. A mould is produced by sediment filling of an empty shell after its inhabitant, such as ammonite or snail, dies.
Sometimes the shell itself is destroyed but the remaining hardened sediment preserves both its outer shape and its inner surface curvatures. A crack in a tree is like a shell and resin is the sediment, hardened before the wood around it was completely destroyed. Unlike massive drops, stalactites, sometimes compared to flytraps, were created by successive leakages of resin forming them layer by layer. Each of those discharges could trap the insects that rested or moved around the surface of stalactites in the process of their growth. The structure of these amber forms as well as the number and location of arthropods immersed in them have made it possible to reconstruct the process of their formation in detail.
The frequency of leakages was different. When resin surface set and hardened a little, insects would sit on it and dust carried by wind would bring tiny plant remains onto it. Frequently big, stalactites are also formed out of layers of resin discharge, but they are not shaped like typical icicles because they stick to a tree trunk on one side. Both these forms are often naturally separated into layers in the course of being repeatedly moved along with sand or other sediment in which they are deposited. Single crusts, as they are called, may be up to 5 mm thick and they are almost ready specimens for research on tiny creatures. Unlike nearly all amber drops, these unique amber flytraps are wonderfully transparent, which provides an opportunity for detailed studies.
How do various forms of amber arise?
The shape of amber
Evrything You Always Wanted to Know About Amber