Amber will often have inclusions of insects, plant materials, and pyrite. The Greek name for amber is electron which arose because amber can be electrically charged by rubbing it with a cloth (thus attracting dust).

Amber comes in a wide range of sizes, a surprising array of colors, and with endless combinations of inclusions. It is almost always polished into freeform pieces, though occasionally as a cabochon. Since amber is relatively soft, it is best used in neck pieces and earrings.

Amber and alcohol DO NOT MIX. The same denatured alcohol that works so well to clean diamonds can ruin amber. Amber's reaction to alcohol will range from losing a little luster to turning chalky. This is surprising when you realize that amber has virtually no reaction at all to another strong solvent, ether. Apparently alcohol in low concentrations (as in perfumes) will not adversely affect amber. Generally speaking, the lighter more transparent amber will resist alcohol's attack better than the darker opaque ambers. The safe bet: don't mix amber and alcohol.

A great book on amber is Life in Amber by George O. Poinar, Jr. (Stanford University Press, 350 pages, 1992, $55 hardbound). It discusses origins and catalogs the life that has been preserved in amber. It is well illustrated, containing 154 b/w and 37 color photographs.

Localities:

Historically, the main source of amber has been the Baltic Sea area. More recently, the Dominican Republic has become a major amber player. Other sources include Italy, Mexico, and Rumania. At one time, Burma was a significant source, but now you must be careful as "Chinese amber" and "burmite" are misleading names given to imitation amber. It's even been found in South Dakota. 

History and Folklore:

Amber has been used in jewelry for centuries. During the Stone Age and into the Roman Empire, amber linked the Mediterranean with northern Europe. Archaeologists have reconstructed trade routes based on discoveries of hordes of amber. Nero ordered amber expeditions.

The most impressive use of amber was an entire room of amber done in the 18th Century for King Frederick William I of Prussia. It contained wall panels of amber in many shapes and colors, and inlaid amber with intricate carvings. Amber was used to frame the doors and windows, and showcases displayed a myriad of amber carvings and jewelry. Frederick gave this room to Czar Peter the Great of Russia as a present (because he liked it so much), and the entire room was disassembled and relocated to St. Petersburg. The room was moved at least once again, then lost forever in 1941 when the Germans were threatening to invade. The Russians supposedly moved the amber room to underground vaults in the Ural Mountains - and it has not been seen since.

Treatments:

Amber's clarity can be improved by boiling it in rapeseed or linseed oil.

"Sun spangles" can be induced in amber by heating. These are the discoid fractures seen in certain amber that some people consider desirable. Heating amber can also darken yellow amber to a more orangey brown giving it the look of naturally age-oxidized amber.

Dyes and other surface treatments are also sometimes used with amber.

Imitators:

New (young) resins called copal.
Yellow/red/orange glasses and plastics.
Synthetic resins.
Pressed amber (compressed bits and pieces of amber).
Reconstructed amber.

There are several ways of making a distinction between real amber and an imitation, here are some of them.

Because the specific weight of amber /on an average 1.056 g/cm 3/ is not much greater than that of water /1.00 g/cm 3/, amber, as opposed to its imitation, floats on the surface of the solution prepared from 1 l of water and 30 g of table salt. Amber sinks in clean water.

• Amber has electrostatic abilities: rubbing it against for example wool makes it attract to its own surface small, light objects, such as: hairs, tiny pieces of paper, etc.
• After slight heating amber gives off resinous scent.
• Amber with great difficulty melts, and never completely, on well-known solvents

The Origin of Baltic Amber

Baltic amber is mineral resin the age, of which is estimated on 40-50 million years. Originally it was thought that the resin-forming tree was the pine Pinus succinifera. At present the opinion, that the resin was given off by several sorts of the conifers at prevailing participation of one of them, becomes more and more general. Amber-resin-giving forests covered the area of today's Scandinavia and of the Baltic sea. From there resin was transported by a river, the mouth of which was situated opposite today's sea-coasts of the Baltic and gradually changed into amber.

• The greatest ledges of amber are situated along the coast from Chłapów to Sambian Peninsula. However it is not its only place of occurrence. In the period of glaciations secondary deposits of amber dispersed all over Poland come into being.
• Illustration represents:
  - sea borders - blue color,
  - land - dotted line,
  - hypothetical route of the river Eridan
  transporting amber in upper Eocene - red color.