Amber is the name for fossil resin or tree sap, appreciated for its colour and beauty. Although it is not mineralized , it is sometimes considered a gemstone. Most of the world's amber is in the range of 30-90 million years old. It can hold insects or even small mammals, called inclusions.
The English word amber stems from the old Arabic word anbargris or ambergris, which refers to an oily, perfumed substance secreted by the sperm whale, which floats and gets washed up on beaches. Due to a confusion of terms, it also came to be the name for fossilised tree sap, which is also found on beaches.
The presence of insects in amber was observed by Pliny the Elder, which led him to understand that at some point amber had to have been in a liquid state. The Greek name for amber was Electron and was connected to the Sun god, one of whose titles was Elector or the Awakener . The modern term electron was coined in 1891 by the physicist George Stoney, using the Greek word for amber, because of its electrostatic properties.
Probably the most well-known amber in the world is that of the Baltic region and accounts for 80% of the world's known amber resource. From prehistoric times this amber has been used and fashioned
by humankind in countless ways. It is found from the East coast of Britain to the shores of Estonia. Baltic amber is
between 35 to 40 million years old. It contains a signature chemical - succinic acid - hence the name
Succinite for amber originating from this region.
Two types of pine trees have been found to possess succinic acid in their resin - Keteleeria and
Pseudolarix. The latter have been discovered in the Eastern mountain ranges of China, and their growing environment matches that indicted by inclusions found in amber. It seems that once amber-forming forests occupied
the greater part of the Baltic Sea and Scandanavian Penninsula.
Amber occurs within 'Blue Earth' deposits. The largest are in the Samland Peninsula of Kaliningrad, now a Russian enclave on the Baltic Sea.
Here the 'Blue Earth' strata is located approximately 25-30 metres below the surface. The amber bearing layer must also outcrop on the seabed in certain areas, so after a strong storm out at sea amber can be gathered from the beach.
Treatments to clarify or change the colour of amber
Cloudy amber may be clarified in an oil-bath, as the oil fills the numerous pores to which the turbidity is due.
The colour of Baltic amber is sometimes changed artificially, but this is also called "true amber".
Small fragments are now used on a large scale in the formation of "ambroid" or "pressed amber".
The pieces are carefully heated and compressed into a uniform mass by intense hydraulic pressure. This product is
extensively used for the production of cheap jewellery.
Amber has often been imitated by other resins like copal and kauri , as well as by celluloid and even glass.
Semi-fossilized resin or sub-fossil amber is called copal. Often amber (particularly with insect inclusions) is
counterfeited using a plastic resin. Much of this is produced in China.
Testing to see if amber is genuine
Since plastic resin has similar properties to amber, it is often difficult to tell the difference. The best test (short of spectroscopic analysis!) is to touch the material with a red-hot pin and check for the sweet odour of
wood resin. If there is a smell of burning plastic, the material is counterfeit.