amber, inclusions, gems

In the opening pages of “The Tears of Heliades,” E.J. Gübelin recounts the Greek myth of amber’s origin and describes the trade, recovery, and geology of Baltic amber. In the myth, Phaethon loses control of the sun chariot and sets the Earth ablaze. Zeus kills him with a lightning bolt and turns his grieving sisters, the Heliades, into black poplars. Their tears continue to fall and harden into amber. Gübelin lists European occurrences in Denmark, England, the Netherlands, Romania, Sicily, Sweden, and Ukraine, and identifies the Samland Peninsula near Kaliningrad as the principal source. Known since antiquity, its amber was prized in trade and could readily be worked into ornaments, vessels, snuffboxes, amulets, and ritual objects. People traditionally gathered amber from beaches, recovered it with nets, and picked it out of exposed layers along the steep coast. Storms could wash golden-yellow pieces ashore. Gübelin also describes the industrial strip-mining methods used at the time of writing. Excavators removed thick layers of clay to expose the amber-bearing deposits, which were then worked, washed, and screened. The amber occurs about 75–120 feet below the surface in two marine sedimentary layers colored by glauconite and known as “Blue Earth.” A map distinguishes amber-rich deposits, concentrated along the Samland coast, from occurrences of Blue Earth without amber. Gübelin takes the marine fossils and the 19 sedimentary layers above the Blue Earth as evidence of repeated uplift and subsidence over long periods. He notes that amber had been recognized as tree resin since antiquity and explains that its concentration along the Baltic coast once led to the supposition that the source forests had grown where the deposits now lie. He treats the coastal deposits as secondary accumulations and proposes that the source forests covered an ancient landmass encompassing large parts of what are now Scandinavia and the Baltic Sea.