A four-part test determines genuine amber. Place a drop or two of alcohol (isopropanol or ethanol) on the polished surface of the specimen and allow it to evaporate. It will make copal sticky and there will be no reaction to amber or other fake materials. If the sample scratches with a pin it’s amber as glass won’t scratch. Heat a wire or needle until red hot, allow it to slightly cool, then press it against the edge of the sample. It will produce a puff of smoke. If the puff smells slightly acrid resinous it’s amber, if on the other hand the smell is sweet resinous, then its copal. A word of caution: celluloid is flammable and other plastics can give off potentially harmful vapors. Finally, place seven teaspoons of table salt into 12 inches (300 milliliters) of water and stir until salt is dissolved. If the sample floats its either copal or amber all other materials will sink.

Cheers, Dr Reese
http://DrReese.com/