BALTIC AMBER DEPOSITS
Baltic amber can be found along the shores of the Baltic and North seas, with the largest deposits lying in the Sambian Peninsula, in the territory of present-day Kaliningrad in the Russian Federation.
Once under the soil, tree resin would rapidly oxidise and vanish. River streams spared resin from this process, instead carrying it into the sea or lakes. Clay sand with mica impurities was washed far away from the shores of the Eocean sea and this "Blue earth" was deposited near the Eridan River delta on the shores of the presentday Sambian Peninsula. From there sea currents deposited amber along the entire Baltic Sea coastline.
Geological processes such as glacier movement, transporting boulders and rocky earth, meant amber was transported into the North European lowlands.
Depending on the size of amber pieces, streams of melting ice carried amber further still.
Interesting to know:
The condition of amber depends on what sediments it lay in and how deep under the surface of the earth it was.
Amber with a thick, brittle crust would have spent centuries lying above ground water levels.
Amber that lay below the ground water level would oxidise at a much slower pace, that is why its surface crust was much thinner.
(Source: Lithuanian Art Museum, pgm.lt)