Formation
The process of amber formation involves several steps over an extended period of time. The huge forest that covered northern Europe from Southern Scandinavia to the Ukraine and from central Britain to the Ural Mountains was dominated by now extinct distant relatives of the modern spruce, fir and pine trees. These trees were notable for the large amount of resin they produce. Many species of tree produce quantities of resin today particularly spruces. The closest modern living relative to the ancient Amber trees of the Baltic region is the giant Kari tree found in New Zealand which is also an impressive resin producer.
Resin is a sticky substance that the tree releases as a defence mechanism in response to injury, such as a break in the bark or an insect bite. The resin helps to seal wounds and protect the tree from pathogens. Resin is composed of volatile organic compounds, including terpenes and resin acids. These compounds give resin its sticky and aromatic properties. The specific composition of the resin can vary among different tree species.
The resin exudes from the tree and begins to flow down the bark. It can trap and encapsulate various materials, such as insects, plant debris, or even air bubbles, as it flows. Over time, the resin undergoes a process called polymerization. This involves the chemical transformation of the original liquid resin into a more solid, stable substance. Polymerization can be triggered by factors such as exposure to oxygen, sunlight, and microbial action. The resin hardens and solidifies into a substance known as copal. The hardened resin, now copal, may fall to the ground or be washed off the tree by rain. It can then be buried by sediment, such as soil or sand, which helps protect it from environmental factors like decay and microbial activity.
Over millions of years, geological processes come into play. The buried resin becomes subjected to heat and pressure from the Earth's crust. This process, known as diagenesis, continues the transformation of copal into amber. Diagenesis involves the loss of volatile components, leading to the creation of a more stable and fossilized material. The final product, amber, is the result of the complete fossilization of resin. It is distinguished from copal by its age; amber is millions of years old, while copal is relatively younger. The transformation from resin to amber is a gradual process, and the quality and characteristics of the amber depend on factors such as the original resin's composition, the geological conditions it experienced, and the inclusions trapped within.
For resin to be considered to be Amber it has to be sufficiently hard to be used as a gem. This is why we do we not find Amber in conjunction with modern resin producing trees. The general consensus is that true Amber is at least one million years old, any material younger than this is called immature Amber or Copal.
The entire process of amber formation is a remarkable journey through time, preserving not only the resin itself but also providing a unique record of ancient ecosystems and life forms. The inclusions trapped in amber can offer valuable insights into the flora and fauna of bygone eras.
FUN FACT
Unlike most gemstones, amber is not dense and can float in saltwater. This property has been used as a quick test for authenticity, as imitations or substitutes often sink