Amber forms over millions of years. Pine trees produce sticky resin, which flows slowly down the tree, trapping small objects such as feathers, plant materials and even small insects in its path. Air bubbles formed in the resin, which over time became encased in dust and debris. Through the natural processes of heat and pressure the resin fossilised to form amber.
In some cases amber is shaped like a teardrop or stalactite, appearing as it would have emerged from the pine tree. As resin flowed into the cracks and cavities on trees, the resultant amber developed as large, irregularly-shaped gemstones.
Amber and Copal
In order to be classified as amber, the fossilised resin must be over one million years old. Amber deposits have been discovered, ranging from between one million and 360 million years old, belonging to the Carboniferous and Pleistocene geological periods. Copal is also tree resin, but it has not fully fossilised into amber, and is thousands of years old. Many amber deposits from Africa are considered copal rather than genuine amber.
Because both types of stones are formed the same way it can be difficult to identify original amber.
A reliable test is to expose the gemstone to ultraviolet (UV) light – copal glows whiter than amber under a UV light.
The Hardness of Amber
Registering between 3 and 1 on Mohs’ Scale of Hardness, amber is a soft gemstone that should be store apart from other jewellery wrapped in a soft cloth. Amber from Myanmar is the hardest type, measuring 3 on the hardness scale. Baltic amber measures between 2 and 2.5, and is most commonly used in the jewellery industry. At between 1 and 2 Dominican amber is the softest form of this gemstone. Geologically younger amber is softer than specimens that have been buried for millennia.
Valuation and Shades of Amber
Amber’s value increases with the rarity and perfection of a stone’s trapped object. The most highly prized amber gemstones are those containing complete insect samples, but these stones are rare. Amber occur in a wide range of colours, the most common of which is the yellow-brown-orange hue that gives its name to the colour “amber”. Amber hues ranged from an almost white tone, to lemon yellow, brown and almost black.
Other less common colours include red amber – also known as “cherry amber” – green amber and the rare and extremely desirable blue amber, which turns blue in natural sunlight and under partial or total UV light sources. Just 100 kilograms of blue amber is mined annually.
The most highly prized amber is transparent, in contrast to the more usual cloudy amber and opaque amber. Opaque amber is also known as “bony amber”, and contains many tiny air bubbles.
Identifying Counterfeit Amber
Several imitations of amber are available on the market, so it is important to deal with a reputable jeweller or gemmologist when purchasing amber. One imitation is called “Amberdan”, which is very similar to genuine amber. Originality is tested by heating the gemstone, and if the resultant odour smells like a combination of plastic and amber this confirms a natural resin has been mixed with a plastic binder to form amberdan. Genuine amber will give off an odour of incense.
Pressed amber known as “ambroid” is considered an imitation gemstone. Ambroid is created by using heat to fuse together small pieces of amber, so verification of this imitation is clearly visible when examined under a microscope. When a piece of wool is rubbed vigorously on amber it will produce a static charge capable of picking up a tiny piece of ash. Counterfeit amber will not react this way.
A simple test to verify the amber’s authenticity is to touch the surface of the gemstone with a heated pin. An odour is of wood resin means the stone is genuine, although counterfeit amber can be coated with a thin layer of wood resin.
Identification of the insect inclusions inside a piece of amber can also be a good guide to verifying the stone’s authenticity. An amber gemstone containing a modern house fly is almost certainly a fake stone, because the house fly in its current form did not exist millions of years ago. This indicates the insect has been fused into the stone, which means the stone is not genuine. Counterfeit amber usually features a too-perfect pose and position of a trapped insect.
Sources and Uses of Amber
The largest source of Baltic amber is a mine west of Kaliningrad in Russia. Baltic amber is also found in Estonia, Latvia, Lithuania and Poland, and has been washed up on the shores of European countries like Denmark, England and Norway. Germany, Lebanon, Romania, Sicily, Mexico and Canada are also reliable sources of amber. A bed of amber discovered in New Jersey introduced more than 100 previously unknown extinct Cretaceous insect species from 94 million years ago.
Because it is a soft gemstone, amber scratches easily. It should be cleaned with a soft cloth and stored apart from other jewellery wrapped in a soft cloth.
Amber has been used as an ingredient in perfumes, as a healing agent in folk medicine, and to produce ornaments and jewellery. It is also used in the production of smoking and glassblowing mouthpieces. A Danish distillery makes a brand of akvavit – a traditional Scandanavian liquor – distilled with amber.
The History and Mythology of Amber details this unique gemstone’s place in man’s culture.