The ancient allure of amber

 

Stone Age peoples were no doubt captivated by amber's smoothness, warm color and feel, translucence, and resinous fragrance when burned, as well as by the curious insects trapped within it and its ability to attract bits of chaff and straw (because of its static charge). Neolithic people carved amber into figures and symbols, which were worn as special charms. Its oldest and most continuous use has been for adornment, yet amber is not a semiprecious stone or even a mineral; it is tree resin in fossilized form. Unlike other fossils, which are usually mineral replacements of the original structure, amber is entirely organic; over millions of years, its composition changes little from that of the resin that formed it. Amber is found in hundreds of sites around the world, but the largest quantities come from 40-million-year-old deposits in the eastern Baltic region and from 23- to 30-million-year-old deposits in the Dominican Republic and Mexico. The deposits are almost always found in sediments that formed the bottom of ancient lagoons or river deltas. This is probably because the density of solid amber is just slightly less than that of water, so it is buoyant and is easily carried downstream and cast up as beach drift along seacoasts or in the shallows of a river delta. Over time, sediments gradually bury the resin. Baltic amber, or "gold of the North," was collected, carved, and traded throughout Europe and Asia Minor. Baltic amber beads found in Mycenaean tombs of the Middle Bronze Age indicate its value in Greece and Asia Minor about 1500 B.C. Other finds in Greece, Crete, the lonian Islands, Palestine, and Egypt also indicate widespread trade in the material (a recent study even suggests that a number of objects from the tomb of Tutankhamen are of Baltic amber). Between 900 and 200 B.C., the Etruscans used amber extensively in jewelry and decorative objects, and the Romans revived the trade that had lapsed in the Greek period. In the fourth century B.C., Aristotle recognized that amber was petrified tree gum. The Roman historian Tacitus wrote in A.D. 98 that beyond the land of the Goths (a Germanic people from lands bordering the Roman Empire's northern frontier) lived the Aestii people, who gathered amber (which he called "exuded metal") that had been washed up by the Baltic Sea. Tacitus was the first to conjecture that the amber forests were remote from where the amber was found, although he did not understand that the amber About 90 percent of Baltic amber has a high concentration of succinic acid, leading to speculation about the kind of tree or trees that might have exuded the local amber. Pine trees in the genus Pseudolarix (found today only in Asia, Australia, and Chile), produce succinic acid, and 40-million-year-old Pseudolarix cones that have been found in the Canadian Arctic's Axel Heiburg Island sup- port the idea that this tree may have once grown in the northernmost latitudes. Dominican and Mexican amber was produced by a species of Hymenaea tree that is now extinct. Some close relatives, however, still grow and produce resin in Central and South America and in the Caribbean. Most recently amber is attracting attention because of the window it provides into the past. Modern technology has revealed that the tiny organisms embalmed in amber have been preserved to a remarkable degree. Soft tissues (such as muscles) and even cells, cellular details, and DNA are preserved-information unobtainable from any other fossil of like age. by David A.Grimaldi