A BOTANICAL GARDEN

June 6th, 2013

Because of the brittle nature’ of amber, miners work cautiously with _shovel and pick, avoiding dynamite or bulldozers.

Unlike Baltic amber, which is found in easily mined shoreline deposits and sometimes even washes up on beaches, the Dominican supply is located in rugged, nearly inaccessible country. Only in the past 40 years have miners worked these fields. When Christopher Columbus landed in what is now the Dominican Republic on his first voyage to the New World, it was he who pre­sented as a gift to a young Carib chief­tain a string of shiny amber beads. Now the Dominican deposits rate as the most productive in the Western Hemisphere.

Today crude amber, which brings from six to as much as forty dollars a pound, goes primarily to Santo Domingo, where practiced jewelers fashion lumps into ornaments. First the jeweler shaves off the crust with an emery wheel, then shapes the piece to accent inclusions (middle right). Last, he polishes it with a cloth wheel. Among the rarest finds is “blue” am­ber (bottom), shown approximately actual size, which perhaps derives its color from fluorescence created by a peculiar chemical composition.

IMMUNE TO TIME in its amber casket, a primitive wasplike ant (upper left) goes back some 100 million years, making it the oldest ant known to man. Dinosaurs still lumbered across the earth when this half-inch long example of the species Sphecomyrma freyi became imprisoned in resin. The hardened substance was   buried until 1966, when two rock col¬lectors uncovered the treasure in a New Jersey clay formation.

Scientists hail the insect, now in Harvard University’s Department of Fossil Insects, as an important link in the evolution of ants. Though the specimen exhibits certain wasplike character-istics, the structure of the thorax and abdomen qualifies it as a primitive work­er ant. This leads experts to believe that by the Cretaceous Period ants had established their caste system of social organization.

Ants and flies appear most frequently in amber. Insects larger than two inches are rarely seen. Judged a relatively scarce find, a spider slightly larger than a pinhead (lower left) was found in south-central Arkansas, site of a widely studied deposit in the United States. Heavenly bodies also seem to appear in amber. Inside a Dominican Republic piece, two “Saturns” and their orbiting “moons” inhabit a fiery atmosphere (below)—actually air bubbles and in­ternal fractures.

A BOTANICAL GARDEN at first glance, the inclusion below proves to be elaborate air bub­bles. Apparently a tiny crack developed in an already solidified lump of resin; fresh, sticky resin then began to fill the narrow crevice. Air also crept along the fracture plane, thus forming the array of mosslike pseudo-fossils. Some for­eign substance—perhaps iron oxide —colored several of the lacy bubbles.

Studying entrapped plant remains, scientists list ferns, leaves, bark, grass, and flowers like a blossom from the Dominican Republic (upper right), perhaps related to the pokeweed. Such is the clarity of good amber and the state of its inclusions that under magnification the veins of a leaf may still be read like a map (bottom right).