The Dominican Republic has the destinction of having one of the two most extensive deposits of amber in the world, the other being the Baltic Sea area.  Classified as a gem, amber is actually the fossilized resin of extinct species of trees. The source of Dominican amber was the leguminous tree Hymenaea or Algarrobo.  Millions of years ago as these trees toppled and were carried by river systems to the coastal areas, their resins became covered with silt.  Eventually this sediment hardened to rock and the resin hardened to amber.  It takes a minimum of twenty-five million years for amber to form, and though the oldest discovered so far is dated at eighty million years, the oldest Dominican amber dates between thirty-five to forty million years.  There are three main areas on the island where amber is mined, but the oldest and hardest comes from La Cumbre in the Central Mountain Range between Santiago and Puerto Plata.

Amber is mainly valued for its inclusions of fossilized insects, plants, worms, vertebrates, feathers, mushroom caps, animal hair, eggs, flowers, leaves, etc. - the list is varied and endless.  Most inclusions are quite small, however the value raises considerably the larger the piece of amber and the rarer the inclusion.  The colour of amber varies from various shades of yellow, orange, and even to green, blue, and purple.  Blue amber is especially sought after and is one of the rarest to come by, therefore it too is highly valued.  The blue colour is not due to the pigmentation in the stone, but from flourescence when exposed to ultra-violet light which is why these colours will appear pronounced when reflected in sunlight.  Amber can be delicate in that drastic changes in temperature can cause it to fracture, and it will often change to a darker colour and develop surface cracks after a few years of exposure to light. 

A variety of substances has been used over the years to make imitation ambar, such as epoxy resins, plastics, celluloid, polyesters, to name a few, but true amber is distinguishable by its melting temperature, burning ordor, hardness, fluorescence, among many other factors.  A simple test to determine if a piece is fake or real is to add about five tablespoons of salt to a glass of water.  True amber will float but plastic will not.