To satisfy the passion of collectors the inventive genius of falsifiers seems to be nearly inexhaustible. Proceeding on the assumption that nowadays it is possible to find everything ­ from total falsifications up to malicious part restorations ­ (see photo) on the international market of art, the question arises how the collector protects himself from falsifications and financial losses.   The thermoluminescence analysis achieves here amazing things! A lot of minerals have the feature to store energy from a field of radioactive radiation and to radiate it again in form of light impulses, the so­called thermoluminescence "TL". The field is formed by the tracks of non­stable uranium, thorium, potassium and rubidium isotopes, which are nearly everywhere in the earth´s crust. With some exceptions, each clay, which is used for forming objets d´art and articles of daily use, contains such radiosensitive minerals. Quartz and feldspar have a favourite position as supporter of the "TL" feature. The thermoluminescence analysis gives information of the last time of burning. The determination of age in the "TL" certificate refers to the "burning age" of the sample, which means the time of its last heating to a temperature of more than 500° celsius and shows the place where the sample has been taken. To determinate the age, the ceramic samples are heated under conditions of laboratory, through which energy is setting free in form of visible light impulses. This energy is the measure for the radioactive self­ and ambient radiation, which influenced the ceramic minerals since the last burning. The more of the self­ and ambient radiation has been stored, the older the ceramics has to be classified. As therefore the age of ceramics depends on the measure of the free setting energy, an exact determination of age is possible.   Labor Ralf Kotalla, Kätzling 2, D-72401 Haigerloch ­ Weildorf Tel.: 0049­7474/9536­0, Fax: 0049­7474/9536­10, Mobile: 0049(0)171/6228521