More than 5,000 geological and archaeological specimens of amber and related fossil resins have been analyzed by infrared spectrophotometry in the Amber Research Laboratory atVassar College since 1964. Statistics show that 97. 5% of the samples of authentic Baltic amber (succinite) can be recognized as such by computer classification of the infrared spectra. The remaining 2.5% fall into two categories: (1) Samples that are so extensively weathered that they have lost all characteristic features, and (2) Samples that have been treated with natural or synthetic resins in the course of conservation measures. The latter group can often be identified by assigning the extraneous absorptions to known contaminants or by partial solvent extraction of the contaminants. The demonstrated reliability of the infrared method has led the Union Internationale des Sciences Prehistoriques et Protohistoriques to establish a Committee on the Study of Amber and to charge it with the production of a Corpus Sucinorum Veterum: i.e., a comprehensive inventory and analysis of all the amber finds of ancient Europe. Sporadic objections to the method are based on unsupported theories about the botanical sources and the geological history of Baltic amber; they are irrelevant to the empirical provenience analysis of archaeological amber artifacts. See also AATA 19-1932 for related paper. -- AATA