Infrared spectrometry
Effective and non-invasive identification of Baltic amber is possible.
Infrared spectrometry is the most commonly used spectroscopic method of analyzing Baltic amber (succinite) and other natural and artificial resins, often constituting the basis for their identification.
The use of this method in the study of fossil resins began in 1963-1964 in three research centers: in Germany, the USA and Russia. In Poland, the work of T. Ratajczak from 1968, who used this method to study chalk resins from the Moravia region, can be regarded as the beginning of research on infrared resins.
In Poland, infrared spectra are obtained by two methods - transmission and reflection. In the Amber Laboratory operating at the Amber Museum, the reflection method is used in an ATR spectrometer. This method in Poland is becoming more and more popular. It is a fast, effective, and most importantly non-invasive method for identifying Baltic amber as a raw material and products made from it.
The testing of amber using a spectrometer with an ATR reflection adapter consists in placing amber or a product made of it on a diamond crystal plate. Then, using a special clamp, the test sample is attached in such a way that the radiation beam reflects off the sample and records the signal. We obtain a spectrum by examination. It presents a series of intense spectral bands that are used to identify natural and artificial resins. For the test result to be correct, the sample must have a smooth, reflective surface or fracture.
From numerous spectral analyzes carried out in our laboratory, we can certainly conclude that there are no major difficulties in distinguishing Baltic amber from copals or imitation amber from modern resins. Comparing the spectra of Baltic amber with the spectra of the Colombian copal at first glance you can see the difference between these two graphs. The most typical diagostic feature of Baltic amber is the so-called "Baltic arm". The copal spectrum is distinguished by a greater number of spectral bands and narrower and more clearly separated peaks compared to Baltic amber. First of all, we don't see the "Baltic arm" in the spectrum of copal.
An obstacle in identifying amber may be covering the surface of the tested amber with a "protective" layer. The examiner should be aware that the reflected light penetrates only a thin surface without going into the sample.
The laboratory operating at the Amber Museum offers authenticity testing of amber and its products along with the issue of a certificate. The cost of testing with issuing the certificate is PLN 50.