Amber is ancient, hardened tree resin, sometimes millions of years old, making it an organic gemstone rather than a mineral. Because it is highly sought after, the market is heavily saturated with synthetic materials and younger resins like plastic, glass, and immature copal. Understanding reliable testing methods is the only way to confirm a piece’s authenticity before purchase.
Initial Visual Assessment
The first step in determining authenticity involves a careful visual inspection, often under magnification. Genuine amber rarely displays perfect uniformity in color or clarity, often showing subtle, natural variations called striae. These irregular flow lines were created as layers of resin hardened over time and typically appear swirling throughout the specimen.
Another telling sign is the appearance of air bubbles trapped within the material. In authentic specimens, these bubbles are often numerous, tiny, and may appear slightly elongated. Suspicious pieces, especially those made of plastic or glass, frequently exhibit a manufactured perfection, lacking the natural, slightly waxy warmth of true fossilized resin.
Inclusions, such as insects or plant matter, should also be scrutinized. Fakes often contain specimens that are too large or placed too centrally. Natural inclusions are usually minute and appear randomly positioned, reflecting the chaotic nature of sticky resin trapping life. A piece that looks too flawless or contains a large, perfectly centered insect should raise immediate suspicion.
Simple Practical Home Tests
The most accessible and least destructive method for initial testing is the saltwater float test, which relies on genuine amber’s specific gravity. To perform this, create a supersaturated solution by dissolving approximately seven teaspoons of salt into eight ounces of water. Authentic amber will float easily in this dense solution, while glass and most plastics, which are significantly denser, will sink.
Copal, the younger, semi-fossilized resin, also usually floats, meaning this test eliminates glass and plastic but not younger resin. A hardness test can provide further differentiation, as genuine amber is relatively soft, registering between 2 and 2.5 on the Mohs scale. Attempting to scratch the piece with a fingernail or a copper coin may leave a very faint mark on real amber, but it should not scratch glass.
Plastic and glass impostors are significantly harder and resist light abrasion, whereas copal is often softer and more prone to damage. Applying vigorous friction is another simple, non-destructive method that can provide olfactory and electrostatic clues. Rubbing the piece quickly and firmly against a piece of wool or cotton cloth will generate static electricity.
This static charge is strong enough for the genuine material to pick up small, lightweight objects like tiny paper scraps or hair. If the rubbing continues long enough to generate significant heat, real fossilized resin will emit a faint, pleasant, pine-like odor. Fakes, however, typically produce an acrid, chemical scent, or simply no smell at all.
Thermal and Fluorescence Testing
Moving beyond simple friction, applying direct heat offers a more definitive, though potentially destructive, analysis. The hot needle test requires heating a needle tip until it is red-hot and carefully pressing it into an inconspicuous spot, like a drill hole. Real amber is relatively brittle and will crack slightly when the needle touches it, producing a thin wisp of white smoke.
The resulting smell is highly characteristic, often described as a strong, pungent pine or burning wood scent. Conversely, a plastic fake will melt immediately, often pulling into a stringy thread, and will release a distinctively acrid or chemical odor. Younger copal will also melt more readily than true amber, confirming its less mature state.
A less invasive, yet highly specialized test utilizes ultraviolet (UV) light, which causes genuine amber to fluoresce. When exposed to UV light, authentic specimens typically glow with a distinctive pale blue or green hue. This reaction is caused by specific chemical compounds within the fossilized resin.
While some modern plastics are engineered to mimic this effect, they often fluoresce a bright, uniform white or a different shade, lacking the soft, natural glow of the ancient material. This UV test provides strong supporting evidence of the material’s composition, though it cannot distinguish between amber and all forms of copal.
Identifying Common Amber Impostors
The most common material used to simulate authentic amber is copal, which is tree resin that has only partially fossilized, often being thousands rather than millions of years old. Copal is softer and more volatile than true amber, easily failing the hot needle test by melting quickly and sometimes exhibiting a stickier texture when scratched. While technically real resin, it lacks the age and stability of true amber.
Synthetic impostors fall mainly into two categories: glass and various plastics. Glass is easily identified because it is cold to the touch, sinks in the saltwater test, and cannot be scratched by a coin. Plastics are created to closely mimic the appearance of real pieces but fail the heat test by melting with a chemical smell and often have a density that causes them to sink or float unnaturally.
A final, distinct category is ambroid, or “pressed amber.” This is not a fake but rather small fragments or dust of genuine amber that have been heated and compressed together. Ambroid is less valuable than a single, natural piece because the heating process alters the internal structure, making it appear too uniform and often creating visible “flow marks” where the pieces fused. Ambroid will pass most chemical tests because the material is technically real, but it is not a natural solid piece.