Natural raw baltic amber has a thin bark. To see the natural beauty of amber jeweler have to polish it and natural color of amber shows up. Baltic amber has seven main colors, and about 250 shades.
Transparent amber (with a yellowish shade). About 10% of amber are transparent, but this is mostly found in small pieces. Big transparent amber pieces are especially rare and valuable. This colour of amber could be called ``primary``. The shade of transparency could change from yellowish to dark red; it depends on the degree of amber oxidation. If successive streams of resin were laid in layers, the amber was formed foliated. Most inclusions are found in this particular amber.
Red amber. Natural red shade is especially rare. Red shades can vary from orange to dark red. Red amber was formed when the amber stayed in the air for a long time: oxidation process, heat of the sun, fire in the forest. Natural oxidation takes place in the air and the amber interacts with oxygen and changes its colour step by step. Transparent amber becomes more red; yellow and other colours become more concentrated. This is very long process: change in the shades of colour could be noticed only after 50-70 years. ``Old`` amber is highly valued because of its ``maturity“.
Yellow amber. This is the most common colour of amber (about 70% of all colours). Resin was flowing from trees in the heat of the sun and the volatile components of resin evaporated and made them turbid - thousands of small gas bubbles were formed. These bubbles defract the light forming the yellow colour. In one square millimeter of yellow amber could be 2500 gas bubbles 0.05-0.0025 mm. in diametre. The more bubbles, the lighter the shade of yellow.
White amber is very rare. Usually this amber is distinguished by its variety of textures and ``natural ornamentation``. Amber of this colour is also called ``Royal`` or ``Bony``, some people take white amber for ivory. It can be with some ``colourful intrusions`` (yellow, black, blue, green, transparent amber) with interesting patterns. The volatile materials of resins evaporated very intensively in the sun heat and resin obtained the form of foam. The more micro-bubbles amber has, the whiter it is. White amber is easier than other colors amber and it floats even in fresh water. Appearance of colour intrusions could be explained by resin of the same amber piece not flowing simultaneously; for example: flowing resin did not foam in a cloudy day, but after that they mixed with resin that had already foamed or with some impurities that had got into resins, bringing their own special shade.
Greenish amber is rare. Greenish shade and sometimes ``crystal``/``sugar`` structure was formed, after resin fell on plants and reacted with pigment chlorophyll that could be found in plants. Because of the crystal structure, sometimes green amber is called ``sugar`` amber.
Black amber. This is a rather frequent colour of amber. Resin was thoroughly mixed up with the remains of the bark and leaf litter mass. Sometimes there could be only 10-15% of resin, and the other being impurities. Therefore, black amber is more fragile than other colours of amber and it is difficult for artists to work with it.