The Colours of Amber

The natural colour of amber is light yellow or honey-tinted. It was probably the colour of the resin of the prehistoric Pinus succiniferea. The darker colours of other types of amber are a result of oxidation. The external layer is often rough and cracked, and is called cortex. The Polish Amber Industry have over 200 names for their national gemstone. Some named 'goose fat', 'egg yolk' and 'cherry', based on the transparency and colour. Other descriptive words include 'banana', 'ivory', 'milky' and 'lemon'. The rarest colours of natural amber are blue, green, white and kumst (sauerkraut colour).

Microscopic bubbles of gas within the gemstone determine the natural colour of the Baltic Amber. Brilliant Green Amber is the 'gem quality' honey amber that has been heat enhanced. As with most gems, there are enhancement techniques to enliven and brighten the stone. Remember the natural green amber is rare and would not be so bright with inclusions and 'sun spangles'.

Currently jewellers are applying a dark paste to the backs of the amber gems. They then heat the amber in an autoclave to clarify it and cause the fractured discs - the illusion of the green amber. The heated amber is still considered 'gem quality'. Milky, creamy and lemon amber are examples of natural colours which have not been heated and they do not have the 'sun spangles'. White and opaque kinds of amber have a structure of foam. The colour and degree of transparency depends on the number and size of the air-holes. The most foamy ones have almost one million air-holes per square millimetre.