Tests for identifying Real Amber from Fake
Smell. Amber is known for its special smell which is difficult to imitate in fake amber. When a piece of Baltic or real amber is rubbed between the palms or heated, the characteristic aroma of pine resin will be felt. Imitations emit different smells: copal emits a "sweet" smell, while others will smell like burning plastic.
Hot needle test. When a heated needle is poked into the surface of a piece of amber, a pine resin smell will be felt, but it won't be ' possible to create a deep hole. A needle enters imitation plastic pieces easily, even all the way through to the other side. But be careful not to ruin your jewellery - the imprint of a burn cannot be removed from amber.
Solubility. If the surface of a piece of amber is rubbed with spirit, ether or a piece of cotton wool dipped in acetone, and the cotton wool sticks to the surface and the amber piece leaves a stain, it means it is an imitation.
Salty water. Dissolve two spoons of table salt mixing them into a glass of water and add a few pieces of amber - they won't sink to the bottom. This test does not work with polystyrene or copal because their comparative weight is similar to amber. These two materials will also float to the top. If the jewellery contains metal details, they will cause the Baltic amber to sink.
IR-spectroscopy. Infra-red spectrums may be used to determine fake amber. All the materials used in producing imitations have their own specific spectrums and are easily identifiable. The IR spectrum range, called the "Baltic shoulder", is typical only to Baltic amber.
(Source: Lithuanian Art Museum, pgm.lt)