Monday, April 14, 2008

The solution: Amber

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In my last addition to my weekend fun series I presented a orange, slightly translucent little "rock". It was correctly recognised and described by EffJot as amber! Due to weathering effects the surface of the amber is covered with cracks and fractures and developed a surface incrustraction that has likely been abraded by transport and subsequent re-sedimentation. The specimen you see here is of Eocene age and was found by a friend of mine in a small gravel pit in northern Germany close to the Baltic Sea. I am sorry Silver Fox but what you interpret as breccia texture is likely nothing more than the weathering cracks and surface features of the hardening resin. There are no visible inclusions in this specimen except some tiny air bubbles (I wonder if it's worth examining those). The origin of amber is, to make it short, fossilised tree resin that hardened under exposure to air and was then deposited in sediment and re-sedimented. The German name for amber "Bernstein" is likely derived from the lower German word "börnen" which means something like "to burn". This is closely linked to the fact that amber can easily be burned.

There is only one major and active amber mine to my knowledge. It is located in the area of the former Königsberg, now part of the Russian exclave of Kaliningrad. The open pit is called Primorskoye in Jantarni and the amber is part of the so called "Blue Earth" that holds a considerable content of Glauconite that is respondsible for its color and name. They are also of Eocene age. Of course amber can be found in many parts of the world. A lot of you likely remember if from Jurassic Park!

A good source that gives a great overview to Baltic amber is: Baltischer Bernstein by Ulf Erichson and Dr. Wolfgang Weitschat published by the Deutsches Bernsteinmuseum Ribnitz-Damgarten. That little book is also my source here.

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